C.S. Lewis began broadcasting his Christian talks on BBC radio in 1941.
During the Second World War, Lewis delivered a series of radio talks for the BBC beginning in 1941. The talks explained basic Christian ideas in language intended for a broad public audience rather than a specialist theological readership.
The broadcasts were later revised and collected in book form. Their principal published result was Mere Christianity, first issued in Britain in 1952 after earlier printed versions titled Broadcast Talks and Christian Behaviour. The final book became one of Lewis’s most influential works of Christian apologetics.
The broadcasts are sometimes described as if they were originally a single book. In fact, they began as spoken talks, were adapted for print, and were later organized into the familiar structure of Mere Christianity. Their wartime setting also explains the emphasis on shared moral reasoning and clear, accessible language.