Frederick Houk Borsch, since 1988, has been Bishop of the Episcopal Diocese of Los Angeles. I don't remember where I first read this quote on the Trinity, but my notes indicate that when he wrote it, he was a religion Professor of Religion at Princeton University and Dean of the Princeton University Chapel.

There are probably a number of people who imagine that the idea of the Trinity was thought up by ivory-tower theologians who, typically, were making things more complicated than they needed to be and were obscuring the simple faith of regular believers. In fact, it seems that the process worked pretty much the other way around. Practicing believers and worshipers were driven by their experiences of God's activity to the awareness that God related in several different ways to the creation....

Thus what these believers came to insist upon was that God had to be recognized as being in different forms of relationship with the creation, in ways at least like different persons, and that all these ways were divine, that is, were of God. Yet there could not be three gods. God, to be the biblical God and the only God of all, had to be one God. This complex and profound faith was then handed over for the theologians to try and make more intelligible. They have been trying ever since.