Mere Christianity develops C.S. Lewis’s Christian belief through talks first broadcast by the BBC during World War II.
Lewis delivered the original radio talks in three series between 1941 and 1944. They were aimed at a broad British audience during wartime, and Lewis used direct, conversational language rather than an academic lecture style. The broadcasts discussed morality, Christian doctrine and the differences between ordinary Christian belief and denominational disagreements.
The talks were later revised and collected into book form. The title Mere Christianity refers to the shared core of belief held by many Christian traditions, not to a separate denomination. The book became one of Lewis’s most influential works of Christian apologetics.
The work is often remembered for the “trilemma” discussion concerning Jesus, but that argument is only one part of the book. Lewis also develops his famous analogy of a hallway leading to different rooms, using it to distinguish shared Christianity from individual church traditions.