If Christianity should happen to be true, then it is quite impossible that those who know this truth and those who don’t should be equally well equipped for leading a good life. Knowledge of the facts must make a difference to one’s actions. Suppose you found a man on the point of starvation and wanted to do the right thing. If you had no knowledge of medical science, you would probably give him a large solid meal; and as a result your man would die. That is what comes of working in the dark. In the same way a Christian and a non-Christian may both wish to do good to their fellow men. The one believes that men are going to live for ever, that they were created by God and so built that they can find their true and lasting happiness only by being united to God, that they have gone badly off the rails, and that obedient faith in Christ is the only way back. The other believes that men are an accidental result of the blind workings of matter, that they started as mere animals and have more or less steadily improved, that they are going to live for about seventy years, that their happiness is fully attainable by good social services and political organisations, and that everything else (e.g., vivisection, birth—control, the judicial system, education) is to be judged to he ‘good’ or ‘bad’ simply in so far as it helps or hinders that kind of ‘happiness’…. The Christian and the Materialist hold different beliefs about the universe. They can’t both be right. The one who is wrong will act in a way which simply doesn’t fit the real universe. Consequently, with the best will in the world, he will be helping his fellow creatures to their destruction.C.S. Lewis, “Man or Rabbit?” published as a pamphlet for the Student Christian Movement in Schools (probably 1946) and God in the Dock (Eerdmans: 1970) 108-109.