Which C.S. Lewis book presents his wartime radio talks on Christianity?

Mere Christianity presents C.S. Lewis’s wartime radio talks on Christianity. The talks were broadcast by the BBC during the Second World War and later revised into printed form under the title Mere Christianity.

Lewis began the first series in 1941, followed by additional broadcasts in 1942 and 1944. He aimed to explain shared Christian ideas in language understandable to listeners from different denominations. The talks discuss morality, human nature, Christian belief, and the meaning of faith.

The phrase “mere Christianity” refers to the core beliefs historically shared by many Christian traditions. Lewis did not intend the book to function as a complete statement of one denomination’s theology. Its conversational style helped it reach a wide audience in Britain and later internationally.

The book is sometimes confused with The Problem of Pain, an earlier 1940 work addressing suffering. The two books are related in subject but have different origins and purposes.