The BBC aired the wartime radio talks that were later revised into C.S. Lewis’s Mere Christianity.
Lewis delivered the talks during World War II, beginning in 1941, for the BBC’s religious broadcasting service. The broadcasts were intended for a broad British audience and presented shared Christian ideas rather than the distinctive doctrines of one denomination.
The talks were later published in stages as Broadcast Talks, Christian Behaviour, and Beyond Personality. Lewis revised and combined this material into the book Mere Christianity, first published in 1952. The title refers to the central beliefs held in common by many Christian traditions.
Mere Christianity is therefore not the verbatim transcript of one single broadcast series in book form. It is a revised literary work based on several wartime radio talks. The BBC’s role helped make Lewis’s voice familiar to a large public before his later books reached an even wider international readership.