Which C.S. Lewis book developed from wartime radio talks broadcast in Britain?

Mere Christianity developed from wartime radio talks broadcast in Britain by C.S. Lewis. The talks were delivered between 1941 and 1944 and later revised and published as a book in 1952.

The work presents what Lewis regarded as the central beliefs shared by the major Christian traditions. It is arranged in four parts: “Right and Wrong as a Clue to the Meaning of the Universe,” “What Christians Believe,” “Christian Behaviour,” and “Beyond Personality.”

Lewis was invited to speak by James Welch, the BBC’s Director of Religious Broadcasting. His broadcasts reached a large audience during the Second World War, when radio was an especially important medium for public communication.

The title does not refer to a denomination. “Mere Christianity” means the common core of Christian belief that Lewis believed existed beneath disagreements among churches. The book is therefore an apologetic work rather than a novel or autobiography.