Our Father is not, according to Jesus, merely our Father. He is our Father "who art in heaven." What does that mean? Getting at the answer to that in our present culture is harder than you'd think, not least because heaven, says C. S. Lewis, is an acquired taste. There are moments, he writes, when he wonders whether we really desire heaven. I know how he feels. I grew up as a pagan. That's not to say I grew up worshipping Apollo or painting myself with woad and running around naked in the woods (a vision...