Of all the doctrines of the Christian faith honored in name and neglected in practice by evangelicals, the Trinity probably has no rival. Ask any evangelical if he believes in the Trinity, and you will almost certainly receive a strongly affirmative answer. Ask what difference the doctrine makes, and you might well be greeted by embarrassing silence.
Two Common Errors: Modalism and Tritheism
Prayer is often a good measure of someone's theology. Our guard tends to drop a little when we pray. The words we speak reveal our theology at its most instinctive level. Most of us will have heard (perhaps some of us have even spoken) prayers that thank God the Father for dying on the cross at Calvary. The intention may be good, but the theology is awful. It is what theologians call patripassianism, the notion that God the Father suffered for us. It is a type of modalism, the idea that God is one but has morphed over time from Father to Son to Holy Spirit. It fails because it simply cannot make sense of the New Testament's teaching on the interpersonal relationship of Father, Son, and Spirit. After all, if the Father is, in a sense, the Son, then to whom is Jesus talking in his high priestly prayer in John 17?
Modalism is not the only heresy into which evangelicals can accidentally fall. There is the opposite problem of tritheism, the idea that Father, Son, and Holy Spirit are so separate that they can even be thought of as being in opposition to each other. Perhaps one common manifestation of this relates to the notion of atonement. Evangelicals know that God is angry against sin and that Christ takes the punishment for our sin upon his own shoulders. Yet sometimes this can be understood in a way that raises problems for the doctrine of God. It is not uncommon to hear Christians, and sometimes even pastors, speak as if God the Father is angry with sin in such a way that he has to be persuaded by his Son, on the basis of the latter's sacrifice, to look with kindness and mercy upon us.
This latter view is problematic because it fails to see two basic biblical truths. First, the plan of salvation is the plan of God the Father, and thus it cannot be the case that Christ is somehow in opposition to him. Indeed, is that the obvious implication of Jesus' prayer in Gethsemane (Luke 22:42)? Second, the New Testament points clearly toward the fact that Jesus is God: he forgives sins, which only God can do (Luke 5:20-21; cf. Ps. 103:3); he considered it not robbery to be equal with God (Phil. 2:6); and he was the Word made flesh (John 1:14). The importance of this is that it has to be the case that both Father and Son will the same thing. They are not two gods, each struggling to impose his will upon the other. They are one God, united in saving purpose.
We might also add confusion over the role of the Spirit at this point. How many prayers are addressed to the Spirit? How many worship services seem preoccupied with talking and singing about the Spirit? Pardon the pun, but sounding so spiritual does not really capture the role of the Spirit, as we shall see. More correctly, we should remember that the role of the Spirit is to witness to Christ. Like a flashlight in the dark, the Spirit illuminates the Savior. When looking for something in a darkened room with a flashlight, we do not typically talk about the flashlight but rather about what the flashlight is illuminating. Indeed, we would typically only talk about the flashlight in such circumstances if it was not working or we did not have one. That has serious implications when we apply it to constant talk about the Spirit.
Does It Really Matter?
Of course, one of the responses to this will be: What difference does it make? So what if my prayers are worded a little loosely, or if I think of God the Father and God the Son as being in some opposition to each other? Does it change how I live as a Christian? There are a number of responses to this.
First, it is important to understand that we ought to have appropriate and accurate thoughts of God. God has revealed himself to be and to act in a certain way. We are to strive to conform our thoughts of God as closely to his revelation as is possible. That is one reason why we listen to good preaching, read good books, and meditate upon Scripture's teaching. As Christians, we want to know the God we worship so we might worship him better.
Second, there are actually some immediate practical benefits that come from a proper Trinitarian understanding of God. For example, think of how it enhances prayer. The Bible teaches that Christ is the One who intercedes for us. If we think of Christ and the Father as being in some kind of opposition to each other, then the success of Christ's prayer always depends upon his persuasive powers and the willingness of the Father to be persuaded. Perhaps today the Father will listen to Christ, but tomorrow he might change his mind. That serves to undermine our own confidence in our prayers. Our prayers are tenuous enough anyway, without adding a further weak link in the prayer chain by misunderstanding the relationship between the Son and the Father.
If, however, Father and Son are one God and will precisely the same things, then we know that the Son's intercession must succeed. When he prays to his Father, he is merely asking for that which the Father desires to give him. What tremendous practical confidence that gives to believers when they come to the Lord in prayer. As Christ takes our prayers, perfects them, and presents them to the Father, he asks for nothing that the Father is not already eager to grant in abundance. The Spirit also plays his role. As the bond of union with Christ, he is intimately connected to our prayers, and’as Paul so beautifully yet mysteriously states’he too intercedes for us in our weakness. The same applies to his prayers: as he is God with the Father and the Son, he joins them in the holy confluence of intercession and divine will.
Trinitarianism is very trendy among theological academics, both evangelical and liberal, yet it has to grip the imagination of typical believers. While the language of Trinitarianism is common among evangelicals, the importance of it for piety and everyday practice is perhaps not so obvious. Yet the usefulness of the doctrine, both in making sense of Scripture's teaching and in forming the foundation of a healthy Christian life, especially in terms of prayer, is incalculable. Pastors and preachers need to spend time reminding and teaching, by precept and pious example, the importance of the doctrine for even the humblest Christian.
