What was the core message of Jesus of Nazareth? It is there in the opening chapter of the gospel of Mark: "The time is fulfilled, and the kingdom of God is at hand." That "kingdom," of course, is not one of this world but one of the spirit, which Jesus stated clearly to Pontius Pilate. And just as we need food (the staple of which is bread) to live in the world, we also need spiritual food to live in the world of the spirit. The purpose of this...