Does a Christian expect that ultimate reality, when and if we get to experience it, will really be like what we might experience or discuss in a church?
Yes and no. When we hear about Moses and the prophets brought into the presence of God, hear of the disciples at the Transfiguration, of John seeing visions in Patmos, the Christian does not then think, “Oh yes of course, that’s precisely what I experience every Sunday at eleven.” There is a distance between the experience of ordinary Christian life and the direct and full awareness of God.
Still, the Christian understanding will want to insist there is some direct relationship between the prayers and teachings and rituals of the faith on the one hand, and that ultimate eternal reality on the other side. The faith stands as a preparation, an anticipation, an approximation, a guarantee, a glimpse.
As C. S. Lewis wrote, what the Christian faith says about God and the last things might be more like the outline of the coast on a map, than it is like the coast itself. Thus, it’s still valuable for its purposes, but it’s is completely impossible to get it confused with that toward which it is pointing us.
Still, that doesn’t mean that some kind of an experience of ultimate reality is not available in this life. As the list above (Moses, the prophets, the apostles, etc) should indicate, it is indeed possible from a Christian standpoint, even though human speech is not entirely adequate to communicating what may be found there.
So, in some way there is the possibility of a Christian mysticism. But then, what about non-Christian mystics? What is the relationship of their experience to reality, and to Christian teaching? What may initially seem like a deeply perplexing problem, here, turns out to have a simple answer.
We might first think that the Christian is faced with the unhappy decision of having to say either that the non-Christian mystic is some sort of misguided counterfeit, or else that Christianity itself is dispensable and unnecessary. However, the Christian is actually able to respond simply that on the Christian account, the divine will is free to bestow grace on whomever God wishes. Thus, we need not discount or reject the testimony of non-Christian mystics entirely, even if their interpretations of their own experiences won’t always line up with how a Christian would want to express them.
There’s been suspicion toward the term “mysticism” among some groups of Christians in recent decades, because it has come to be associated with a variety of strange and not-greatly-admired movements. Still, as a term with a long philosophical and religious history before the recent shift, and as a term that captures such an important part of the religious way of approaching the world, I really believe it deserves to be renewed.