When rightly understood, the imaginatively compelling story of the birth of Jesus of Nazareth was about God entering the world, in order to redeem it.
Lewis explored this theme in a remarkable sermon that he preached in a London church during the Second World War. He had learnt how to dive in 1930. Although he initially saw this simply as an enjoyable, exhilarating experience, Lewis began to realise its potential as an analogy for what he was coming to see as a core theme of the Christian faith ”” the incarnation.
Lewis invited his audience to imagine a diver plunging into the water to retrieve a precious object. As he goes deeper, the water changes from “warm and sunlit” to “pitch black” and “freezing”. Then, his “lungs almost bursting”, he goes down into the “mud and slime”, before finally heading back up to the surface, triumphantly bearing the lost object. God “descended into his own universe, and rose again, bringing human nature up with him”.
Read it all (subscription required) [this is quoted in the sermon in the previous post].