Which C.S. Lewis book presents Christianity through talks originally broadcast by the BBC?

Mere Christianity presents C.S. Lewis’s Christian ideas through talks originally broadcast by the BBC. The broadcasts began during the Second World War, with the first series transmitted in 1941 and later series following in 1942 and 1944.

Lewis was invited to speak about Christianity to a broad radio audience. His style was conversational and direct, avoiding specialized theological vocabulary where possible. He began with moral experience and the idea of a shared moral law, then discussed Christian belief, behavior, and the central doctrines of the faith.

The talks were later revised and published in book form. The title Mere Christianity refers to the core beliefs shared across many historic Christian traditions, rather than to one denomination. Lewis was an Anglican, but the book was intended to explain foundational Christianity to listeners from varied backgrounds.

The work is sometimes confused with The Problem of Pain, which was published in 1940 and addresses suffering, or with Miracles, published in 1947. Mere Christianity grew directly out of Lewis’s wartime radio broadcasts and became one of his best-known nonfiction books.