C.S. Lewis developed Mere Christianity from talks broadcast by the BBC. During the Second World War, he delivered a series of radio talks that explained basic Christian beliefs to a general audience.
The talks were broadcast between 1941 and 1944 and were later revised and collected in book form. The resulting volume, Mere Christianity, appeared in 1952. Lewis was invited to speak because of his clear, accessible style and his ability to present religious ideas without relying on specialist academic language.
The book is arranged in sections commonly known as “Right and Wrong as a Clue to the Meaning of the Universe,” “What Christians Believe,” and “Christian Behaviour.” Lewis intended to describe shared Christian convictions rather than defend one particular denomination.
The BBC was then a central source of national radio programming in Britain. Lewis’s broadcasts reached listeners during wartime and helped establish him as a public religious writer before Mere Christianity became a widely read book.