C. S. Lewis’s wartime talks for the BBC were adapted into Mere Christianity.
During the Second World War, Lewis delivered a series of short Christian broadcasts for BBC radio. The talks were intended for a broad listening public and explained basic Christian ideas in accessible language rather than presenting a detailed denominational system.
The talks were later revised and collected in book form. Mere Christianity was published in 1952, bringing together material associated with the broadcast series and earlier printed versions. Its central aim was to present what Lewis regarded as common Christian beliefs shared across major traditions.
The title does not mean that Lewis invented a new denomination called “Mere Christianity.” The phrase refers to the shared core of belief he believed existed beneath disagreements among churches. Lewis’s radio work also helped make his voice familiar beyond universities and literary circles.