C.S. Lewis’s BBC broadcast talk series later published as Mere Christianity was titled Broadcast Talks. Lewis delivered the talks during the Second World War, and they were adapted into books that eventually formed the well-known volume Mere Christianity.
The broadcasts began in 1941 and were intended for a general audience rather than for specialists in theology. Lewis used direct language and everyday examples to explain shared Christian beliefs. The talks were later revised and collected in stages: The Case for Christianity, Christian Behaviour, and Beyond Personality.
Mere Christianity was published as a single volume in 1952. The title refers to the common core of beliefs shared across many Christian traditions, not to a separate denomination founded by Lewis. Because the later book became much more famous than the original broadcasts, readers sometimes incorrectly call the wartime radio series Mere Christianity from the outset.