Which C.S. Lewis book presents Christianity through talks originally broadcast during World War II?

Mere Christianity presents Christianity through talks originally broadcast during World War II.

The book grew from a series of radio broadcasts Lewis delivered for the BBC between 1941 and 1944. He aimed to explain shared Christian beliefs in accessible language rather than argue for one particular denomination.

The broadcasts were later revised and collected into three sections: “Right and Wrong as a Clue to the Meaning of the Universe,” “What Christians Believe,” and “Christian Behaviour.” The title refers to the common core of Christian belief Lewis wanted to discuss.

A common mix-up is assuming the book was first written as a conventional treatise. Its early form was spoken radio material, and the broadcast setting helped shape its direct, conversational style. The collected book was published in 1952.