Which C.S. Lewis book presents Christian belief through radio talks broadcast during World War II?

Mere Christianity presents C.S. Lewis’s Christian arguments developed from wartime radio talks.

The talks were broadcast by the BBC during World War II, beginning in 1941. Lewis was invited to speak to a broad public audience, and his clear, conversational style made complex theological ideas accessible to listeners. The broadcasts were later revised and published in book form.

The title refers to the central beliefs shared across historic Christian traditions, rather than to one denomination. Lewis discusses morality, human nature, belief, and the Christian understanding of God, while generally avoiding detailed disputes between churches.

Mere Christianity is often confused with The Problem of Pain, which examines why suffering exists, and with Miracles, a philosophical defense of the supernatural. It is also separate from Lewis’s BBC children’s programs and from his fictional works. The book’s origins in radio broadcasting explain its direct tone and chapter-like structure.