Which C.S. Lewis book collects his wartime radio broadcasts about the Christian faith?

Mere Christianity collects C.S. Lewis’s wartime radio broadcasts about the Christian faith. The broadcasts were delivered for the BBC during the Second World War and later revised and arranged as a book.

The original talks were broadcast in three series between 1941 and 1944. Lewis first published them in separate forms as The Case for Christianity, Christian Behaviour, and Beyond Personality. The combined title Mere Christianity was used for the 1952 book edition.

Lewis aimed to explain central Christian beliefs in language accessible to a broad audience rather than argue for one denomination. He used ideas such as moral law, human behavior, and the meaning of Christian doctrine to build his case.

The title does not mean weak or minimal Christianity. “Mere” refers to the common core of beliefs shared across many Christian traditions. Readers sometimes identify the book as a transcript of one uninterrupted broadcast series, but it developed from several related radio talks and later editorial revisions.