Which C.S. Lewis book developed from radio broadcasts first delivered during World War II?

Mere Christianity developed from radio broadcasts C.S. Lewis delivered during World War II. The talks were broadcast by the BBC between 1941 and 1944 and later revised and collected as a book.

Lewis’s aim was to explain shared Christian beliefs rather than defend one particular denomination. He organized the material around themes including morality, belief, and Christian practice, using accessible language for a broad radio audience.

The book is divided into sections based on the original broadcast series. Its title refers to what Lewis considered the central or common features of Christianity, not to a separate denomination called “Mere Christianity.”

The broadcasts made Lewis widely known beyond academic and literary circles. The later book became one of his most influential works of Christian apologetics, although readers should distinguish its popular format from a formal church catechism.