The Idea of God, Is It a Leap?

The idea of God makes an awful lot of sense of some very basic human intuitions and actually allows us to take them a lot further. Lewis is saying this deep perception that there is something beyond this that we ought to be obeying tells us something about maybe the way God is, but also things about how we are. We're in a mess and we can't get out of it by ourselves. That's a key theme throughout mere Christianity.