Mere Christianity
by C.S. Lewis
First published 1943 · English · 190 pages
- Philosophy
- Religion and spirituality

This is a work of Christian explanation based on radio talks Lewis gave in Britain during the Second World War. It sets out, in plain and friendly language, the case for belief, starting from the human sense of right and wrong. He then considers the nature of God, the Christian view of human life, and how faith might change behaviour, including questions of virtue, pride and love. Lewis avoids church disputes and aims at what believers across denominations hold in common. The book remains widely read by believers and sceptics alike for its clear reasoning and conversational tone.
Quotes
This year, or this month, or, more likely, this very day, we have failed to practise ourselves the kind of behaviour we expect from other people.
Some people talk as if meeting the gaze of absolute goodness would be fun. They need to think again. They are still only playing with religion. Goodness is either the great safety or the great danger—according to the way you react to it.
There is one thing, and only one, in the whole universe which we know more about than we could learn from external observation. That one thing is Man. We do not merely observe men, we are men. In this case we have, so to speak, inside information; we are in the know.
My argument against God was that the universe seemed so cruel and unjust. But how had I got this idea of just and unjust? A man does not call a line crooked unless he has some idea of a straight line. What was I comparing this universe with when I called it unjust?