What book title was given to C.S. Lewis’s 1950s collection of BBC talks on Christian belief?

Mere Christianity is the title given to C.S. Lewis’s collection of BBC talks on Christian belief.

Lewis delivered the original radio broadcasts during the Second World War, beginning with The Case for Christianity in 1941. Further talks followed in 1942 and 1944. He later revised and combined the material into the book Mere Christianity, published in 1952.

The title refers to the common core of belief shared by the major historical Christian traditions, rather than to one denomination. The book is not a Bible translation or a commentary on one particular Gospel. Its conversational arguments about morality, belief, and Christian doctrine helped make Lewis one of the most widely read Christian apologists of the twentieth century.