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.
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.
1. 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.
2. 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 informing 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.
Source: Core Christianity | Carl Trueman