Teaching theology affords an incredible opportunity to see how people cope with a doctrine that resists the intellect's instinctive attempts to solve it. It is not, as theologians like Rowan Williams and Thomas Weinandy (two very different thinkers, to say the least) have observed, a puzzle to be solved, but a mystery to be pondered. It's a mystery. Rowan Williams says, drawing on the resources of Eastern Orthodox theology, that 'the doctrine of the Trinity is a crucifixion of the intellect.' So it isn't surprising that students of theology, whether giving the lectures or hearing them, find it difficult.
But it doesn't crucify the intellect to no purpose, nor is it the most difficult of the mysteries of the faith. We might think that Jesus is the answer, but he raised a whole lot of questions for a few hundred years. The incarnation and the atonement present us with mystery just as irreducible as the Trinity. The intellectual life of the believing soul involves contemplating the truths of the faith while holding fast to the knowledge of God's ultimate incomprehensibilty. And nowhere is this more true than in that most difficult, deal-breaking area of theological reflection that we call theodicy. The problem of evil is not, like the Trinity might be, a stumbling block just for the intellect. It confronts us when inexplicable and unjust things happen to us or to those we love, things that make us turn to God in confusion, wondering how a God who is omnipotent and perfectly, completely good, could allow such things to happen. I understand how it ends up being a deal-breaker.
I used to wonder why I still had my faith, after all I did to lose it, and after it was challenged by my experience of life. Eventually I came to see that it wasn't 'mine' to lose, really: it is the faith of the Church, and I participate in it, I don't possess it. But that doesn't explain why I am still hanging around. Probably I owe that to my mother, who taught me lots of songs about Jesus when I was small. They're not the sorts of songs that survived the 1980's, but they impressed upon me a certain understanding of Jesus, one that stayed with me. The core of what I think about Jesus was formed before I was old enough really to be puzzled about how someone could be fully God and fully human.
So I am really glad that when my small son asked me, 'Who is God?' I answered with reference to the Trinity, with the sign of the cross, with the name of the Father and the Son and the Holy Spirit. I could have answered, as I supposed might be more practical, with something about God as the creator, or God as love. These would have been good. But at age three, my son never asked how the one I called God could also be called the Father, the Son, and the Holy Spirit. It isn't like we grow up and suddenly the penny drops, and we grasp how three can be one, how one can be three; we don't mature intellectually such that if we wait long enough to introduce these difficult concepts, we will be able to understand them. Better to get used to a name that names something we don't understand from the get-go, and grow into appreciation of the mystery as we develop intellectually and spiritually.
Now I can imagine lots of objections to that, but they will have to wait for another day.