Which C.S. Lewis book presents Christian ideas through radio talks from World War II?

C.S. Lewis’s Mere Christianity presents Christian ideas developed from radio talks broadcast during World War II. The talks were delivered for the BBC between 1941 and 1944 and later revised into book form.

Lewis was invited to speak by James Welch, the BBC’s director of religious broadcasting. His broadcasts aimed to explain basic Christian beliefs to a general audience rather than defend one denomination. The material was eventually arranged in four sections: “Right and Wrong as a Clue to the Meaning of the Universe,” “What Christians Believe,” “Christian Behaviour,” and “Beyond Personality.”

The title Mere Christianity refers to the shared core of belief that Lewis believed was common to historic Christian traditions. It does not mean that the book is a neutral survey of every religion, nor that it represents a formal church catechism.

The collected book appeared in 1952 and became one of Lewis’s most influential works of Christian apologetics.