5 Things You Should Know about the Doctrine of the Trinity

By Keith Mathison

1. The doctrine of the Trinity is one of the most fundamental doctrines in Christianity.

The Christian doctrine of God is the doctrine of the Trinity, and the Christian doctrine of God is foundational to every other Christian doctrine. There is no doctrine of Scripture (bibliology) apart from the doctrine of God because Scripture is the Word of God. Human beings are created in the image of God. Sin is rebellion against the law of God. Soteriology is the doctrine having to do with the redemptive work of God. The church is the people of God. Eschatology has to do with the final goals and plans of God.

2. The doctrine of the Trinity was not invented at the Council of Nicaea.

There is a popular myth today that the doctrine of the Trinity was invented in the fourth century at the Council of Nicaea. This is not true. In the first centuries of the church, Christians were already teaching the fundamental doctrines they found in Scripture. Scripture teaches that there is one—and only one—God. Scripture also teaches that the Father is God. Scripture teaches that the Son is God and that the Holy Spirit is God. Furthermore, Scripture teaches that the Father is not the Son or the Spirit, that the Son is not the Father or the Spirit, and that the Spirit is not the Father or the Son. Anybody who held these basic propositions of Scripture held to the foundations of the doctrine of the Trinity. Over the centuries, there arose those whose teaching denied or distorted one or more of those biblical teachings. The Council of Nicaea was called to respond to one such teaching—the teaching of Arius, who had denied that the Son is God. The Nicene Creed provided boundaries to ensure that the church teaches everything Scripture affirms.

3. The doctrine of the Trinity is not fully comprehensible to human minds.

The doctrine of the Trinity, along with the doctrine of the incarnation, is one of the great mysteries of the Christian faith. This means that it exceeds the ability of finite human minds to fully grasp. If we treat the doctrine of the Trinity like some kind of math puzzle, requiring only the right amount of ingenuity to solve, we will inevitably fall into one heresy or another. The doctrine of the Trinity is not a Rubik’s Cube. There is nothing in creation that is a precise analogy to the doctrine of the Trinity.

4. Most popular Trinitarian analogies are misleading at best and heretical at worst.

Because there is nothing in creation that is a precise analogy to the doctrine of the Trinity, most popular Trinitarian analogies are misleading at best and heretical at worst. Most end up suggesting that the three persons of the Trinity are three parts of God (e.g., the clover analogy; or the egg shell, yolk, and egg white analogy), or that they are three modes or roles of a unitarian God (e.g., the Father, Son, and Spirit “masks”; or the water, ice, and steam analogies). At best, some analogies are perhaps able to illustrate a certain aspect of the doctrine of the Trinity, but they all tend to deny one or more elements of biblical teaching.

5. Misunderstandings regarding who Jesus is tend to lead to misunderstandings of the doctrine of the Trinity.

In the incarnation, the Second Person of the Trinity, the Son, assumed a human nature, which is united to the divine nature. The human nature includes His body and His soul. This means that the Lord Jesus Christ is God-incarnate. He is one Person with two natures, and those two natures are united in the one Person of the Son without confusion, change, division, or separation. Since both natures are His natures, everything that is true of either nature is said of Him, the one Lord Jesus Christ. However, some things are said of Him according to His divine nature (e.g., being the Creator of the world) and others are said of Him according to His human nature (e.g., getting hungry or thirsty). If we confuse the divine and human natures of Christ, it will easily distort our doctrine of the Trinity, because we will read human attributes into God. For example, the Bible teaches that God is immortal (1 Tim. 6:15–16). In other words, God cannot die. But don’t we believe that Jesus is God? And didn’t Jesus die on the cross? Yes, He did, and He did so according to His human nature. A human can die. A human can suffer. A human can change. Jesus did all of these in His human nature, but we can’t transfer those human attributes into the divine nature. The divine nature cannot die or change or suffer. Similarly, Christ perfectly submitted His human will to the divine will of God, but that doesn’t mean that the divine will of the Son was submitted to the divine will of the Father. Why not? Because there is only one divine will. The Son’s divine will is the same divine will as that of the Father because the Son is God just as the Father is God. To use the language of the Nicene Creed, the Son is homoousios with the Father. If the Son’s divine will is submitted to the Father’s divine will, we no longer have the Trinity. We have polytheism.