I have called Christ the ‘first instance’ of the new man. But of course He is something much more than that. He is not merely a new man, one specimen of the species, but the new man. He is the origin and centre and life of all the new men. He came into the created universe, of His own will, bringing with Him the Zoe, the new life. (I mean new to us, of course:
in its own place Zoe has existed for ever and ever.) And He transmits it not by heredity but by what I have called ‘good infection’. Everyone who gets it gets it by personal contact with Him. Other men become ‘new’ by being ‘in Him’.
This step is taken at a different speed from the previous ones. Compared with the development of man on this planet, the diffusion of Christianity over the human race seems to go like a flash of lightning—for two thousand years is almost nothing in the history of the universe. (Never forget that we are all still ‘the early Christians’. The present wicked and wasteful divisions between us are, let us hope, a disease of infancy: we are still teething. The outer world, no doubt, thinks just the opposite. It thinks we are dying of old age. But it has thought that very often before. Again and again it has thought Christianity was dying, dying by persecutions from without and corruptions from within, by the rise of Mohammedanism, the rise of the physical sciences, the rise of great anti-Christian revolutionary movements. But every time the world has been disappointed. Its first disappointment was over the crucifixion. The Man came to life again. In a sense— and I quite realise how frightfully unfair it must seem to them—that has been happening ever since. They keep on killing the thing that He started: and each time, just as they are patting down the earth on its grave, they suddenly hear that it is still alive and has even broken out in some new place. No wonder they hate us.)
Quotes from Mere Christianity, Part 88
C.S. Lewis, Mere Christianity (1952; Harper Collins: 2001) 221-222.