Which C.S. Lewis book collects his BBC radio talks from the early 1940s?

Mere Christianity collects C.S. Lewis’s BBC radio talks from the early 1940s.

Lewis delivered the talks during the Second World War, beginning in 1941, when the BBC broadcast them to a British audience. He aimed to explain central Christian beliefs in accessible language rather than defend one denomination’s distinctive doctrines. The talks were later revised and assembled in book form.

The title refers to what Lewis called “mere Christianity”: core beliefs shared across major Christian traditions. The book is divided into sections on right and wrong, Christian beliefs, Christian behaviour, and the doctrine of the Trinity. Its “trilemma” discussion about Jesus is among its most frequently quoted passages.

Mere Christianity is not the same work as Christian Behaviour, which was one of the original broadcast series and later became part of the collected volume. The book also differs from The Problem of Pain, which focuses more directly on suffering and the problem of evil.