What is the Trinity?

This much is certain. Had Christian faith merely been a human invention, it would never have had a doctrine of trinity. This doctrine is too thorny to understand, and too difficult to explain, for anyone to have deliberately fabricated it. There is no other religion that has anything remotely like this. No, this is not the fruit of our imagination but a doctrine of the way things are. God is tri-une. And knowing him in his tri-unity is not only central to Christian faith but, without this truth, that faith is not Christian at all.

Given this doctrine's centrality it may seem surprising that we have no single verse in the bible, or even a single passage, that explains how it is that God can be one in being and yet within his being there can be three centers of self-consciousness, the Father, Son, and Holy Spirit. Why is this?

The teaching that God is tri-une has to be constructed from many passages for two main reasons. First, this is so because there are many facets to it. It is not a simple doctrine. And, second, God's disclosure of himself did not take place all at once. He revealed his triune nature only gradually and across large stretches of time. It is therefore revealed across a large swath of Scripture.