By all means! It is intensely rational. Now, I've had the question asked of me, "Is it true that you are a Christian rationalist?" I said, "By no means! That's a contradiction in terms. A rationalist is somebody who embraces a philosophy that sets itself over and against Christianity." And so, while a true Christian is not a rationalist, the Christian faith is certainly rational.
Is Christianity coherent? Is it intelligible? Does it makes sense? Does it fit together in a consistent pattern of truth, or is it the opposite of rational—is it irrational? Does it indulge in superstition and embrace Christians who believe that Christianity is manifestly irrational? I think that's a great tragedy. The God of Christianity addresses people's minds. He speaks to us. We have a Book that is written for our understanding.
When I say that Christianity is rational, I do not mean that the truth of Christianity in all of its majesty can be deduced from a few logical principles by a speculative philosopher. There is much information about the nature of God that we can find only because God himself chooses to reveal it to us. He reveals these things through his prophets, through history, through the Bible, and through his only begotten Son, Jesus.
But what he reveals is intelligible; we can understand it with our intellect. He doesn't ask us to throw away our minds in order to become Christians. There are people who think that to become a Christian, one must leave one's brain somewhere in the parking lot. The only leap that the New Testament calls us to make is not into the darkness but out of the darkness into the light, into that which we can indeed understand. That is not to say that everything the Christian faith speaks of is manifestly clear with respect to rational categories. I can't understand, for example, how a person can have a divine nature and a human nature at the same time, which is what we believe about Jesus. That's a mystery—but mysterious is not the same as irrational.
Mystery doesn't apply only to religion. I don't understand the ultimate force of gravity. These things are mysterious to us, but they're not irrational. It's one thing to say, "I don't understand from my finite mind how these things work out," and it's another thing to say, "They're blatantly contradictory and irrational, but I'm going to believe them anyway." That's not what Christianity does. Christianity says that there are mysteries, but those mysteries cannot be articulated in terms of the irrational; if that were so, then we have moved away from Christian truth.