Mortification of Sin

By John F. MacArthur, Jr. [1]

President and Professor of Pastoral Ministries

It is puzzling how a Christian who has experienced liberation from sin’s dominion can at times give in to temptation in his daily life. The OT account of Agag and the Amalekites is a good illustration of how Christians should deal with sin. They should not try to co-exist with it, but should remove it completely. Saul partially obeyed God’s directive, but Samuel obeyed it to the letter by killing King Agag. Christians obey God’s command to mortify sin by living a life in the Spirit and not acknowledging any obligation to the flesh. Consistent effort to mortify sin in the body comes through a life lived in the Spirit. Mortification is the believer’s responsibility and includes such responsibilities as abstaining from fleshly lusts, making no provision for the flesh, fixing one’s heart on Christ, meditating on God’s Word, praying incessantly, exercising self-control, and being filled with the Spirit. Covering up sin, internalizing it, exchanging it for another sin, or merely repressing it do not equate to sin’s mortification. Continuously and uncompromisingly removing sin—resulting in a conscience free from guilt—is what the process entails.

* * * * *

Mortification abates [sin’s] force, but doth not change its nature. Grace changeth the nature of man, but nothing can change the nature of sin….Destroyed it may be, it shall be, but cured it cannot be….If it be not overcome and destroyed, it will overcome and destroy the soul. 

And herein lies no small part of its power….It is never quiet, [whether it is] conquering [or] conquered. 

Do you mortify; do you make it your daily work; be always at it whilst you live; cease not a day from this work; be killing sin or it will be killing you. John Owen[2]

Every honest Christian will testify that becoming a believer does not erase the tendency to sin. He still derives pleasure from sin. He still struggles with sinful habits. Some of those habits are so deeply ingrained that he still battles them after years of spiritual warfare against them. He falls into appalling, shameful sins. The truth is, he sins daily. His thoughts are not what they ought to be. His time is often wasted on frivolous and worldly pursuits. From time to time his heart grows cold to the things of God. Why does all this happen if sin’s dominion is broken?

God’s Anger Against Amalek

An OT illustration may help to shed light on the Christian’s relationship to sin. In 1 Samuel 15, Samuel anointed Saul and solemnly gave him these instructions from the Lord: “Now go and strike Amalek and utterly destroy all that he has, and do not spare him; but put to death both man and woman, child and infant, ox and sheep, camel and donkey” (v. 3).[3]

God’s command was clear. Saul was to deal ruthlessly with the Amalekites, killing even their infant children and animals. Their whole tribe was to be utterly and mercilessly leveled—no hostages taken.

What would cause a God of infinite love to mete out such a severe judgment? The Amalekites were an ancient nomadic race, descendants of Esau (Gen 36:12). They inhabited the southern part of Canaan and were perennial enemies of the Israelites. They were the same tribe that viciously attacked Israel at Rephidim shortly after the Exodus, in the famous battle when Aaron and Hur had to support Moses’ arms (Exod 17:8–13). They ambushed Israel from behind, massacring the stragglers who were most weary (Deut 25:18). It was a cowardly attack by the most powerful and savage tribe in the whole region. God supernaturally delivered Israel that day, and the Amalekites fled into hiding. At the conclusion of that skirmish, God swore to Moses, “I will utterly blot out the memory of Amalek from under heaven” (v. 14). He actually made it a point of the Mosaic law that Israel was to destroy Amalek:

Remember what Amalek did to you along the way when you came out from Egypt, how he met you along the way and attacked among you all the stragglers at your rear when you were faint and weary; and he did not fear God. Therefore it shall come about when the LORD your God has given you rest from all your surrounding enemies, in the land which the LORD your God gives you as an inheritance to possess, you shall blot out the memory of Amalek from under heaven; you must not forget (Deut 25:17–19, emphasis added).

The Amalekites were fearful warriors. Their intimidating presence was one of the reasons the Israelites disobeyed God and balked at entering the Promised Land at Kadesh-barnea (Num 13:29).

God’s anger burned against the Amalekites for their wickedness. He constrained even the corrupt prophet Balaam to prophesy their doom: “Amalek was the first of the nations, but his end shall be destruction” (Num 24:20). The Amalekites used to harass Israel by coming into the land after crops had been sown and moving through the farmland with their tents and livestock, razing everything in their path (Judg 6:3–5). They hated God, detested Israel, and seemed to delight in wicked and destructive acts.

God’s instructions to Saul, therefore, fulfilled the vow He swore to Moses. Saul was to wipe out the tribe forever. He and his armies were the instrument through which a righteous God would carry out His holy judgment on a sinister people.

The Folly of Partial Obedience

But Saul’s obedience was only partial. He inflicted a crushing defeat upon the Amalekites, routing them “from Havilah as you go to Shur, which is east of Egypt” (1 Sam 15:8). As commanded, he killed all the people, but “he captured Agag the king of the Amalekites alive” (v. 8).

Saul and the people spared Agag and the best of the sheep, the oxen, the fatlings, the lambs, and all that was good, and were not willing to destroy them utterly; but everything despised and worthless, that they utterly destroyed (v. 9).

In other words, motivated by covetousness, they kept all the best possessions of the Amalekites, collecting the spoils of victory, willfully disobeying the Lord’s instructions.

Why did Saul spare Agag? Perhaps he wanted to use the humiliated king of the Amalekites as a trophy to display his own power. Saul seemed motivated only by pride at this point; he even set up a monument to himself at Carmel (v. 12). Whatever his reasons, he disobeyed the clear command of God and allowed Agag to live.

The sin was so serious that God immediately deposed Saul and his descendants forever from the throne of Israel. Samuel told him, “Because you have rejected the word of the Lord, He has also rejected you from being king” (v. 23).

Then Samuel said, “Bring me Agag, the king of the Amalekites” (v. 32).

Agag, evidently thinking that his life had been spared and feeling pretty confident, “came to him cheerfully.” “Surely the bitterness of death is past,” he said.

But Samuel was not amused. He told Agag, “As your sword has made women childless, so shall your mother be childless among women.” Scripture simply says, “And Samuel hewed Agag to pieces before the Lord at Gilgal” (v. 33).

The human mind instinctively recoils at what seems to be a merciless act. But it was God who commanded this to be done. This was an act of divine judgment to show the holy wrath of an indignant God against wanton sin. Unlike his countrymen and their king, Samuel was determined to carry out the Lord’s command entirely. As it was, the battle intended to exterminate the Amalekites forever ended before the goal was reached. Scripture records that only a few years later, the reinvigorated tribe raided the southern territory and took all the women and children captive—including David’s family (1 Sam 30:1–5).

When David found the marauding Amalekites, “behold, they were spread over all the land, eating and drinking and dancing because of all the great spoil that they had taken from the land of the Philistines and from the land of Judah” (v. 16). He slaughtered them from twilight until the next evening, killing all but four hundred who escaped on camels (v. 17).

The Amalekites are a perfect illustration of the sin that remains in the believer’s life. That sin—already utterly defeated at the cross—must be dealt with ruthlessly and hacked to pieces, or it will revive and continue to plunder and pillage his heart and sap his spiritual strength. He cannot be merciful with his Agag, or indwelling sin will turn and try to devour him. In fact, the sin remaining in Christians often becomes more fiercely determined after the gospel initially overthrows it.

Scripture commands believers to deal with their sin by putting it to death:

Mortify therefore your members which are upon the earth; fornication, uncleanness, inordinate affection, evil concupiscence, and covetousness, which is idolatry: for which things’ sake the wrath of God cometh on the children of disobedience (Col 3:5–6, KJV).

They cannot obey partially or halfheartedly as they seek to eliminate sin from their lives. They cannot stop while the task remains incomplete. Sins, like Amalekites, have a way of escaping the slaughter, breeding, reviving, regrouping, and launching new and unexpected assaults on their victims’ most vulnerable areas.

Life in the Spirit

In Rom 8:13 Paul also wrote of “putting to death the deeds of the body.” After declaring victory over sin in Romans 6, then describing the ongoing struggle with sin in chap. 7, he describes the triumphant experience of life in the Spirit throughout chap. 8. In the middle of that chapter, the apostle declares that the distinctive behavior of those who are led by the Spirit is that they continually put their evil deeds to death.

It is significant that the Holy Spirit is mentioned only once in the introduction to the epistle (1:4, “the Spirit of holiness”), and not mentioned again until Rom 8:1. In Romans 8 alone there are at least twenty references to the Holy Spirit.

Romans 8 portrays the Holy Spirit as the divine agent who frees believers from sin and death (vv. 2–3), enables them to live righteously (4–13), assures and comforts them in their affliction (14–19), preserves and sustains them in Christ (20–28), and guarantees their final victory in eternal glory (29–39). Right in the context of this profound teaching about the Holy Spirit’s role in the Christian’s life, Paul has some important things to say about mortifying sin. He begins by contrasting life in the Spirit with life in the flesh and under the law. It is important to understand these truths in their proper context:

What the Law could not do, weak as it was through the flesh, God did: sending His own Son in the likeness of sinful flesh and as an offering for sin, He condemned sin in the flesh, in order that the requirement of the Law might be fulfilled in us, who do not walk according to the flesh, but according to the Spirit. Those who are according to the flesh set their minds on the things of the flesh, but those who are according to the Spirit, the things of the Spirit. For the mind set on the flesh is death, but the mind set on the Spirit is life and peace, because the mind set on the flesh is hostile toward God; for it does not subject itself to the law of God, for it is not even able to do so; and those who are in the flesh cannot please God. However, you are not in the flesh but in the Spirit, if indeed the Spirit of God dwells in you. But if anyone does not have the Spirit of Christ, he does not belong to Him. And if Christ is in you, though the body is dead because of sin, yet the spirit is alive because of righteousness. But if the Spirit of Him who raised Jesus from the dead dwells in you, He who raised Christ Jesus from the dead will also give life to your mortal bodies through His Spirit who indwells you (vv. 3–11, emphasis added).

In other words, life in the Spirit is markedly different from the life of the unbeliever. All true Christians are “in the Spirit.” They “do not walk according to the flesh, but according to the Spirit.” Those who walk according to the flesh are unbelievers, and Paul is quite definite in making that clear: “If anyone does not have the Spirit of Christ, he does not belong to Him” (v. 9). Later he adds, “For all who are being led by the Spirit of God, these are sons of God” (v. 14).

In other words, there are only two kinds of people in the world’those who are in accord with the flesh and those who are in accord with the Spirit. Of course, there are in-the-Spirit people at many different levels of spiritual maturity. In-the-flesh people also come in varying degrees of wickedness. But everyone is either “in the flesh” (v. 8) or “in the Spirit” (v. 9). There is no category called “in between.”

What Paul suggests is that the Holy Spirit changes a person’s basic disposition when he is born again. He brings him into accord with Himself. He actually indwells him (vv. 9, 11). Christians become partakers of the divine nature (2 Pet 1:4). Their orientation to God changes. Where there was enmity, there is now love (cf. Rom 8:28). In the flesh they could not please God (v. 8), but now the righteous requirement of the law is fulfilled in them (v. 4). Central to all of this is the reality that their whole mind-set is new. Whereas the mind set on the flesh meant death, the mind set on the things of the Spirit results in life and peace (v. 6).

If your mind-set—the fundamental orientation of your understanding, its bent, its thought patterns—did not change when you made a profession of faith in Christ, something is seriously wrong. That is not to suggest that Christians cannot fall into old patterns and habits. But it does mean that now that they are “in the Spirit,” their thoughts toward God, sin, and righteousness are radically different from when they were “in the flesh.” They have new holy affections and longings for godliness. They have a love for God that transcends their attachment to this world (Jas 4:4). They can no longer blithely “indulge the flesh in its corrupt desires” (2 Pet 2:10). They no longer have anything in common with those “who set their minds on earthly things. For our citizenship is in heaven” (Phil 3:19–20). And it is toward heaven that their minds are now inclined. They set their minds on the things of the Spirit (Rom 8:5). Even when they fail or fall to earthly temptations, they “joyfully concur with the law of God in the inner man” (7:22). That is their basic orientation and mind-set.

In contrast, “the mind set on the flesh is death” (v. 6). Paul does not say that the mind set on the flesh causes death. He declares that it is death. The state of mind that is dominated by fleshly desires is a condition of spiritual death. In other words, those whose thoughts and desires are altogether fleshly are already “dead in [their] trespasses and sins” (Eph 2:1). This cannot be a description of the true believer in Christ.

Christians are no longer “in the flesh”: “You are not in the flesh but in the Spirit, if indeed the Spirit of God dwells in you. But if anyone does not have the Spirit of Christ, he does not belong to Him” (Rom 8:9). The Greek word for “dwells” is οἰκέω (oikeō), which means “I inhabit.” Paul says that the very Spirit of God indwells every person who trusts in Jesus Christ. The Spirit is in believers, and they are “in the Spirit.” They are not “in the flesh.”

Death in the Physical Body

But they are still “of flesh,” and therefore their physical bodies deteriorate and die. The germ of death inhabits them all. Because of the curse of sin, they begin to die as soon as they are born.

For the Christian, however, this earthly life has more than death: “If Christ is in you, though the body is dead because of sin, yet the spirit is alive because of righteousness” (v. 10). In other words, the human body is subject to death (and is already dying) because of sin, but the believer’s spirit is already alive in Christ. Eternal life is his present possession. Though the body is dying, the spirit is already endowed with incorruptibility.

In v. 10 the word “body” clearly refers to the actual physical body (not the flesh-principle), and the expression “dead” speaks of physical death. Notice that vv. 10 and 11 use the word “body” (σῶμα [sōma]) instead of “flesh” (σάρξ [sarx])—the word Paul used throughout the first nine verses. By contrasting “the body” and “the spirit” in this way, he makes his meaning inescapable. In verse 10, “the spirit is alive” refers to the human spirit, the immaterial part of man’s being. The body may be dying because of sin, but the believer’s spirit is fully alive and thriving “because of righteousness”—because he is justified and therefore already has “passed out of death into life” (John 5:24). Paul simply says here what he also told the Corinthians, “Though our outer man is decaying, yet our inner man is being renewed day by day” (2 Cor 4:16).

In fact, the indwelling Spirit also promises “life to [our] mortal bodies” in a future resurrection with a glorified body (v. 11).

Paul’s point is that the body apart from the Spirit of God has no future. It is subject to death. Therefore the Christian has no duty to the mortal side of his being:

So then, brethren, we are under obligation, not to the flesh, to live according to the flesh—for if you are living according to the flesh, you must die; but if by the Spirit you are putting to death the deeds of the body, you will live (Rom 8:12–13).

Again Paul uses the word sarx (“flesh”) in the sense of “sin principle”—and equates it with “the deeds of the body.” If you live in accord with the flesh—if you live in response to bodily impulses—you “must die.”

Paul once more draws the line of distinction as clearly as possible between Christians and non-Christians. He is by no means warning believers that they might lose their salvation if they live according to the flesh. He has already made the point that true believers do not and cannot live in accord with the sin principle (vv. 4–9). Besides, Paul began this chapter with the statement, “There is therefore now no condemnation for those who are in Christ Jesus” (8:1). He will end it with the promise that nothing can separate Christians from the love of God in Christ Jesus (vv. 38–39). A warning of the possibility of falling away would contradict the very purpose for which he was writing.

Paul simply reiterates what he says again and again throughout his NT epistles—that those whose lives and hearts are altogether fleshly are not true Christians. They are already spiritually dead (v. 6), and unless they repent, they are headed for eternal death. Meanwhile, their earthly lives are a kind of abject bondage to sin. They are enslaved to their own flesh, constrained to cater to its sensual desires.

What Is Mortification?

Christians, on the other hand, have a different obligation—not to the flesh, but to the new principle of righteousness embodied in the Holy Spirit. Therefore they labor by the power of the Spirit to mortify sin in the flesh—to “[put] to death the deeds of the body.” If you do this, he says, “you will live” (v. 13).

Of course, Paul does not suggest that anyone can obtain life or merit God’s favor by the process of mortification. He is saying it is characteristic of true believers that they put to death the deeds of the body. Nothing is more natural than for people “led by the Spirit of God” (v. 14) to mortify their sin. One of the proofs of their salvation is that they do this. It is expected of them. It is the expression of their new nature.

In other words, the true believer is not like Saul, who wanted to pamper and preserve Agag, but like Samuel who hacked him to pieces without mercy and without delay. Saul may have wanted to make a lap dog of Agag, but Samuel knew that was utterly impossible. Similarly, a believer will never tame his flesh. He cannot mollycoddle his sin. He must deal with it quickly and severely.

It was Jesus who said,

If your right eye makes you stumble, tear it out, and throw it from you; for it is better for you that one of the parts of your body perish, than for your whole body to be thrown into hell. And if your right hand makes you stumble, cut it off, and throw it from you; for it is better for you that one of the parts of your body perish, than for your whole body to go into hell (Matt 5:29–30).

Jesus was not speaking in literal terms, of course, though many have misunderstood the passage that way. No less than the great theologian Origen had himself castrated in a misguided effort to fulfill this command literally. Jesus did not call for self-mutilation, but for mortification of the deeds of the body. Mortification, in the words of Puritan John Owen, means that

‘The old man,’ with his faculties, and properties, his wisdom, craft, subtlety, strength; this, says the apostle, must be killed, put to death, mortified,—that is, have its power, life, vigour, and strength, to produce its effects, taken away by the Spirit.[4]

Rom 8:12–13, the verses where Paul introduces the idea of mortifying sin, signal a major turning point in the logical thread that runs through Romans 8. Martyn Lloyd-Jones said,

It is here for the first time, in this chapter, that we come to the realm of practical application. All we have had up to this point has been a general description of the Christian—his character, his position. But now the Apostle has really come explicitly to the doctrine of sanctification. Here we are told exactly how, in practice, the Christian becomes sanctified. Or, to state it differently, here we are told in detail and in practice how the Christian is to wage the battle against sin.[5]

Paul does not promise immediate freedom from sin’s harassment. He does not describe a crisis-moment sanctification, where the believer is immediately made perfect. He does not tell the Romans to “let go and let God” take over while he sits idle. He does not suggest that a turning-point “decision” will solve the matter once and for all. On the contrary, he speaks of a continuous struggle with sin, where he is persistently, perpetually “putting to death the deeds of the body.”

The language is often misunderstood. Paul is not calling for a life of self-flagellation. He does not say believers should starve themselves, wear camel-hair shirts, or deprive themselves of life’s basic needs. He is not telling them to mutilate themselves or live monastic lives or anything of the sort. The mortification Paul speaks of has nothing to do with external self-punishment. It is a spiritual process accomplished “by the Spirit.”

Paul is describing a way of life where Christians seek to throttle sin and crush it from their lives, sapping it of its strength, rooting it out, and depriving it of its influence. That is what it means to mortify sin.

How Does a Christian Mortify Sin?

Mortification involves the cultivation of new habits of godliness, combined with the elimination of old sinful habits from one’s behavior. It is a constant warfare that takes place within the believer. Although a Christian should expect his triumph over sin to be ever-increasing, his mortification can never be wholly complete before he is glorified. He is to remain perpetually committed to this task. He must see sin as a sworn enemy, and commit himself to slaying it wherever and whenever it rears its head.

Obviously, mortification is the work of believers only. Unbelievers are called to repent and flee to Christ. Those still enslaved to sin have no means by which to put sin to death. The Holy Spirit—the agent of mortification—does not indwell them. Their only hope is the salvation offered to those who will trust Jesus Christ and entrust themselves to Him. No one can mortify sin who is not “in Christ” and “in the Spirit.”

Scripture offers several practical means whereby believers can mortify their sin. Their growth in grace depends on their obedience to these duties. None of them is a fleshly or mechanical formula. They are not religious activities or rituals. John Owen observed that most of the Roman Catholic religious system consists of

mistaken ways and means of mortification….Their vows, orders, fastings, penances, are all built on this ground; they are all for the mortifying of sin. Their preachings, sermons, and books of devotion, they look all this way.[6]

But sin cannot be annihilated through legalism, monasticism, pietism, asceticism, pharisaism, celibacy, self-flagellation, confessional booths, rosary beads, hail Marys, or any other external means. The instrument of mortification is the Holy Spirit, and His power is the energy that works in Christians to carry out the process. All the means of mortification are simple commands of Scripture that they are to obey. The following will highlight some of the key ones.

Abstain from fleshly lusts. Peter wrote, “Beloved, I urge you as aliens and strangers to abstain from fleshly lusts, which wage war against the soul” (1 Pet 2:11). In other words, stop lusting. Abstain from it.

Stay away from it. “Flee immorality” (1 Cor 6:18). What could be more direct?

Do you want to put to death the lusts in your heart? Then stop entertaining them. Peter does not prescribe a program of therapy. He does not suggest that it be treated as an addiction. He simply says abstain. Quit doing it. You have no business indulging such thoughts. Put them away at once. You yourself must do this; it cannot be done for you. There is no point waiting for some heavenly power to erase this sin automatically from your life. You are to stop it, and stop it immediately. Martyn Lloyd-Jones said,

I do not know of a single scripture—and I speak advisedly—which tells me to take my sin, the particular thing that gets me down, to God in prayer and ask him to deliver me from it and then trust in faith that he will. 

Now that teaching is also often put like this: you must say to a man who is constantly defeated by a particular sin, “I think your only hope is to take it to Christ and Christ will take it from you.” But what does Scripture say in Ephesians 4:28 to the man who finds himself constantly guilty of stealing, to a man who sees something he likes and takes it? What am I to tell such a man? Am I to say, “Take that sin to Christ and ask him to deliver you?” No, what the apostle Paul tells him is this: “Let him that stole, steal no more.” Just that. Stop doing it. And if it is fornication or adultery or lustful thoughts, again: Stop doing it, says Paul. He does not say, “Go and pray to Christ to deliver you.” No. You stop doing that, he says, as becomes children of God.[7]

Here is perhaps the most straightforward, obvious means of mortifying sin: stop doing it. Too many people think they must wait for an extraordinary experience, a miracle from heaven, a sign from the Lord, or whatever. They think some special divine intervention is necessary to free them from a sinful practice or pattern of thinking. No, that is precisely the error Romans 6 refutes. You are free from sin; now stop doing it. “Abstain.” Reckon yourself dead to sin, and do not do it anymore. “Resist the devil and he will flee from you” (Jas 4:7). It is as simple as that.

Make no provision for the flesh. In Rom 13:14 Paul writes, “Put on the Lord Jesus Christ, and make no provision for the flesh in regard to its lusts.” In other words, simply refuse to accommodate fleshly lusts. If you struggle with gluttony, stop loading up on junk food when you shop at the market. If you are tempted with sexual desire, refrain from filling your mind with images that feed your lust. If you do not want to fall, do not walk where it is slippery. Refuse to furnish your mind with the means to entertain evil thoughts. Make no preparations for the possibility of sin. Thus you can slay sin before it breeds.

Fix your heart on Christ. The apostle John wrote, “We know that, when He appears, we shall be like Him, because we shall see Him just as He is. And everyone who has this hope fixed on Him purifies himself, just as He is pure” (1 John 3:2–3). It is an inexorable spiritual law that you become like the object of your worship. Psalm 135 says,

The idols of the nations are but silver and gold, the work of man’s hands. They have mouths, but they do not speak; they have eyes, but they do not see; they have ears, but they do not hear; nor is there any breath at all in their mouths. Those who make them will be like them, yes, everyone who trusts in them (vv. 15–18, emphasis added).

If the heathen become like the lifeless gods they worship, how much more like Christ will Christians become, since they have the Holy Spirit working to accomplish that very goal? As they fix their hearts on Christ, they discover their worship has the effect of conforming them to His image: “But we all, with unveiled face beholding as in a mirror the glory of the Lord, are being transformed into the same image from glory to glory, just as from the Lord, the Spirit” (2 Cor 3:18).

Meditate on God’s Word. The psalmist wrote, “Thy word I have treasured in my heart, that I may not sin against Thee” (Ps 119:11). The Lord told Joshua,

This book of the law shall not depart from your mouth, but you shall meditate on it day and night, so that you may be careful to do according to all that is written in it; for then you will make your way prosperous, and then you will have success (Josh 1:8).

Do you want to have success in the battle against sin? Familiarize yourself with the Word of God. Meditate on it “day and night” (cf. Ps 1:2). Let it be a lamp to your feet and a light to your path (Ps 119:105). As the truth begins to penetrate your heart and mind, it will confront and attack your sin.

Jesus prayed, “Sanctify them in the truth; thy word is truth” (John 17:17). The truth of God’s Word is the medium the Holy Spirit uses in sanctification. Load your mind with it. Fill your heart with it. Ponder it carefully and let it direct your walk.

Whatever is true, whatever is honorable, whatever is right, whatever is pure, whatever is lovely, whatever is of good repute, if there is any excellence and if anything worthy of praise, let your mind dwell on these things (Phil 4:8).

“Let the word of Christ richly dwell within you” (Col 3:16). You will discover that “the sword of the Spirit, which is the word of God” (Eph 6:17) is the most effective weapon for hacking the flesh to pieces.

Pray without ceasing. On the night Jesus was betrayed, He took His disciples with Him to Gethsemane and told them, “Pray that you may not enter into temptation” (Luke 22:40). Later He found them sleeping and rebuked them for their prayerlessness. He told them, “Keep watching and praying, that you may not enter into temptation; the spirit is willing, but the flesh is weak” (Matt 26:41).

“Lead us not into temptation” was part of the model prayer He gave the disciples (Luke 11:4). Prayer is an effective and necessary means for heading off sinful temptations before they can attack. Look at prayer as a preemptive strike against fleshliness. By drawing a believer near to the Lord and focusing his thoughts on Him, prayer both steels against fleshly temptation and weakens the temptations when they come.

Watch and pray. Identify the circumstances that lead you into sin, and pray specifically for strength to face those situations. Pray for a holy hatred of sin. Pray that God will show you the real state of your sinful heart. The psalmist prayed this prayer for sanctification:

Who can discern his errors? Acquit me of hidden faults. Also keep back Thy servant from presumptuous sins; let them not rule over me; then I shall be blameless, and I shall be acquitted of great transgression. Let the words of my mouth and the meditation of my heart be acceptable in Thy sight, O Lord, my rock and my Redeemer (Ps 19:12–14).

Prayer must include confession and repentance if it is to be effective in mortifying sin. John wrote, “If we confess our sins, He is faithful and righteous to forgive us our sins and to cleanse us from all unrighteousness” (1 John 1:9). And the writer of Hebrews says, “Let us therefore draw near with confidence to the throne of grace, that we may receive mercy and may find grace to help in time of need” (Heb 4:16).

Exercise self-control. Self-control is a fruit of the Spirit (Gal 5:23)—and it is also one of the means through which the Spirit enables Christians to mortify the deeds of the body. Paul wrote,

Everyone who competes in the games exercises self-control in all things. They then do it to receive a perishable wreath, but we an imperishable. Therefore I run in such a way, as not without aim; I box in such a way, as not beating the air; but I buffet my body and make it my slave, lest possibly, after I have preached to others, I myself should be disqualified (1 Cor 9:25–27).

The word “buffet” in that passage is a translation of the Greek word ὑποπιάζω (hupopiazō), meaning “to strike under the eye.” Athletes discipline their bodies for mere earthly prizes. If they are willing to do that, should not Christians also be willing to exercise a similar kind of self-control for the heavenly prize?

Paul does not speak of punishing the body through self-flagellation or neglect. He certainly does not advocate anything that would physically weaken or injure the body. No athlete would do such things.

The present writer once met a man who wore a belt studded with nails that constantly tore at his flesh. He felt he was punishing his body and atoning for his own sins. Many misguided people over the ages have attempted similar means to deal with the body. Martin Luther as a young monk almost destroyed his body with excessive fasting before he discovered that God’s Word says, “The just shall live by faith” (Rom 1:29). In the Philippines at Easter each year, there are men who actually have themselves crucified in a bloody ritual that they believe makes them holy.

That is not at all the spirit of what Scripture calls for. It is a watchful self-discipline that refuses to pander to the appetites of the body at the soul’s expense. Jesus said, “Be on guard, that your hearts may not be weighted down with dissipation and drunkenness and the worries of life, and [the Day of the Lord] come on you suddenly like a trap” (Luke 21:34).

Be filled with the Holy Spirit. “Do not get drunk with wine, for that is dissipation,” Paul wrote, “but be filled with the Spirit” (Eph 5:18). To be Spirit-filled is to be controlled by the Holy Spirit, just as to be drunk is to be under the influence of alcohol. Believers are to be utterly yielded to the Spirit’s control.

This brings the discussion full circle to its beginning in Rom 8:13. Christians mortify sin “by the Spirit.” It is the Holy Spirit’s power in them that actually does the work of mortification in those who yield to Him. Once again, however, it is emphatically true that this does not mean they are passive in the process. As John Owen wrote,

He doth not so work our mortification in us as not to keep it still an act of our obedience. The Holy Ghost works in us and upon us, as we are fit to be wrought in and upon; that is, so as to preserve our own liberty and free obedience. He works upon our understandings, wills, consciences, and affections, agreeably to their own natures; he works in us and with us, not against us or without us; so that his assistance is an encouragement as to the facilitating of the work, and no occasion of neglect as to the work itself.[8]

In other words, it is worth repeated reminders that Christians cannot abandon their own responsibility and passively wait for God to mortify sin on their behalf. The Spirit-filled life is an active, vigorous, working endeavor, where they work out their own salvation with fear and trembling (Phil 2:12). When they obey, they then discover it is actually God who is at work in them “both to will and to work for His good pleasure” (v. 13). God both molds their wills to obey and then gives them the energy to work according to whatever pleases Him. That is the Spirit-filled life.

There are many more duties related to mortifying sin—such as clothing oneself with humility (1 Pet 5:5), having the mind of Christ (Phil 2:5), putting away spiteful feelings toward others (Eph 4:31–32), putting on the armor of God (Eph 6:11–17), laying aside sinful attitudes (Col 3:8–9), adding the graces of spiritual growth to one’s life (2 Pet 1:5–7), following the know, reckon, yield, obey, serve pattern of Romans 6. This basic category of being filled with the Spirit encompasses all of these.

It is really as simple as this: “Walk by the Spirit, and you will not carry out the desire of the flesh” (Gal 5:16). The fruit of the Spirit will overgrow and choke out the works of the flesh.

“Let us [therefore] cleanse ourselves from all defilement of flesh and spirit, perfecting holiness in the fear of God” (2 Cor 7:1).

Strike Sin at Its Head

John Owen wrote, “He that is appointed to kill an enemy, if he leave striking before the other ceases living, doth but half his work.”[9] Christians must be always at the task of mortifying sin. They may slaughter a whole tribe of Amalekites, but if they deliberately permit one Agag to escape, God will not be pleased with their efforts.

The flesh is very subtle and deceptive. A particular sin may leave the believer alone for awhile to make him think he is rid of it. But it can come back with a hellish fury if he is not on guard. Sin perpetually stalks him; he must be continually mortifying it. This is a duty he cannot rest from until he rests in glory.

Give sin an inch, it will take a mile. If it can gain a footing in Christians’ lives, it will send forth roots and grow like kudzu. It will use them and abuse them and inflict as much disaster as possible. Owen wrote,

Every unclean thought or glance would be adultery if it could; every covetous desire would be oppression, every thought of unbelief would be atheism, might it grow to its head….It proceeds toward its height by degrees, making good the ground it hath got by hardness…. Now nothing can prevent this but mortification; that withers the root and strikes at the head of sin every hour, so that whatever it aims at it is crossed in. There is not the best saint in the world but, if he should give over this duty, would fall into as many cursed sins as ever did any of his kind.[10]

Later, he added, “Sin sets itself against every act of holiness, and against every degree we grow to. Let not that man think he makes any progress in holiness while he walks not over the bellies of his lusts.”[11]

Christians are not ignorant of Satan’s devices, the apostle declares (2 Cor 2:11). Neither should they be naive about the subtleties of their own flesh. When Agag comes to them cheerfully, saying, “Surely the bitterness of death is past” (1 Sam 15:32) or when he wants to make friends and declare an end to hostilities—that is when it is most imperative to turn on him and cut him ruthlessly to pieces before the Lord.

Sin is not mortified when it is merely covered up. A Christian can hide his sin from the sight of others, but that is not the same as mortification. If a sin has simply been papered over with hypocrisy, what good is there in that? If conscience has only been daubed, Christians are in a much more dangerous state than before. “He who conceals his transgressions will not prosper, but he who confesses and forsakes them will find compassion” (Prov 28:13). You have not done your duty with regard to your sin until you have confessed and forsaken it.

Sin is not mortified when it is only internalized. If you forsake the outward practice of some evil, yet continue to ruminate on the memory of that sin’s pleasures, beware. You may have moved your sin into the privacy of your imagination, where it is known only to you and to God, but that sin has not been mortified. If anything, it has become more deadly by being married to pretended righteousness. Jesus rebuked the Pharisees for this very thing. They avoided murder, but tolerated hate. They refrained from fornication, but indulged in lustful thoughts. Jesus declared them worthy of eternal hell (Matt 5:21–28).

Sin is not mortified when it is exchanged for another sin. What good is it to trade the lust of the flesh for the lust of the eyes? That lust has not been mortified; it has only changed form. Puritan Thomas Fuller said, “Some think themselves improved in piety, because they have left prodigality and reel into covetousness.”[12] If you succumb to this tactic, your heart is in danger of being hardened by the deceitfulness of sin (Heb 3:13).

Sin is not mortified until the conscience has been appeased. The goal is “love from a pure heart and a good conscience and a sincere faith” (1 Tim 1:5). As long as the conscience remains defiled, it affects a Christian’s testimony.

Sanctify Christ as Lord in your hearts, always being ready to make a defense to everyone who asks you to give an account for the hope that is in you, yet with gentleness and reverence; and keep a good conscience so that in the thing in which you are slandered, those who revile your good behavior in Christ may be put to shame” (1 Pet 3:15–16, emphasis added).

Part of the process of mortification is to work through the issue of guilt. Those who attempt to evade guilt for sin have not properly confessed their sin; therefore they cannot be cleansed and fully forgiven.

If you want to mortify sin, John Owen wrote, “Load thy conscience with the guilt of it.”[13] Contrary to the popular wisdom today, he believed the pangs of guilt were a natural and healthy consequence of wrongdoing. “Be ashamed,”[14] he wrote, for he saw shame as an advantage in the mortification of sin. He correctly understood Paul’s meaning in 2 Cor 7:10: “The sorrow that is according to the will of God produces a repentance without regret.”

Those who give a nod of the head to their guilt, claim the promise of forgiveness, quickly reassure themselves, and then think no more of their wrongdoing are subjecting themselves to the heart-hardening deceit of sin—especially when the sin threatens to become a habit. Let sorrow do its full work in your heart to produce a deep, honest repentance, and those sins will be severely weakened.

Sin is not mortified when it is merely repressed. Some people use diversions to avoid dealing with their sin. They try to drown their conscience with alcohol or drown out their guilt with entertainment and other distractions. When temptation surfaces, they do not give a biblical answer, as Jesus did (Matt 4:4, 7, 10). Instead they seek a fleshly escape route. Of this tendency Martyn Lloyd-Jones said,

If you merely repress a temptation or this first motion of sin within you, it will probably come up again still more strongly. To that extent I agree with the modern psychology. Repression is always bad. “Well, what do you do?” asks someone. I answer: When you feel that first motion of sin, just pull yourself up and say, “Of course I am not having any dealings with this at all.” Expose the thing and say, “This is evil, this is vileness, this is the thing that drove the first man out of Paradise.” Pull it out, look at it, denounce it, hate it for what it is; then you have really dealt with it. You must not merely push it back in a spirit of fear, and in a timorous manner. Bring it out, expose it, and analyse it; and then denounce it for what it is until you hate it.[15]

That is sound advice. Christians should deal with their sin courageously, striking at its head. Subduing it a little bit is not enough. They need to exterminate it, hack it in pieces—seek by the means of grace and the power of the Spirit to wring the deadly life from it.

It is a lifelong task, in which progress will always be only gradual. That may make the fight seem daunting at first. But as soon as Christians set themselves to the work, they discover that sin shall not be master over them, for they are under grace (Rom 6:14). That means it is God who is at work in them both to will and to work for His good pleasure (Phil 2:13). And having begun His good work in them, He “will perfect it until the day of Christ Jesus” (Phil 1:6).

Notes

1. This essay is adapted from President MacArthur’s recently released work The Vanishing Conscience (Word).
2. John Owen, The Works of John Owen (16 vols., 1967 reprint; Edinburgh: Banner of Truth, 1853) 6:177, 6:9.
3. All Scripture quotations are from the NASB unless otherwise indicated.
4. Ibid., 6:8., emphasis added.
5. D. Martyn Lloyd-Jones, Romans: An Exposition of Chapter 8:5–17: The Sons of God (Grand Rapids: Zondervan, 1974), 92, emphasis added.
6. Owen, Works 6:16–17.
7. D. Martyn Lloyd-Jones, Sanctified Through the Truth: The Assurance of Our Salvation (Wheaton: Crossway, 1989) 54.
8. Owen, Works 6:20.
9. Ibid., 6:11.
10. Ibid., 6:12, emphasis added.
11. Ibid., 6:14.
12. Cited in I. D. E. Thomas, A Puritan Golden Treasury (Edinburgh: Banner of Truth, 1977) 264.
13. Owen, Works 6:56.
14. Ibid., 55.
15. Lloyd-Jones, Romans 8:5–17 143.