Which C.S. Lewis work developed from his 1940s BBC radio talks?

Mere Christianity developed from C.S. Lewis’s BBC radio talks of the 1940s. The broadcasts were delivered during the Second World War and later revised and collected as a book first published in 1952.

Lewis was invited to speak to a broad British audience rather than to address a specialist theological readership. He aimed to explain shared Christian beliefs in accessible language, using examples and arguments intended for listeners who might have little formal religious education.

The book is arranged in three major sections: “Right and Wrong as a Clue to the Meaning of the Universe,” “What Christians Believe,” and “Christian Behaviour.” A later section, “Beyond Personality,” discusses Christian ideas about the Trinity and spiritual life.

The title refers to common ground among major Christian traditions, not to a new denomination. Lewis did not present Mere Christianity as a replacement for church membership or detailed doctrinal differences. It is also distinct from The Case for Christianity, an earlier book that incorporated material from the broadcasts.