Which C.S. Lewis book collects his wartime radio talks about basic Christianity?

Mere Christianity collects C.S. Lewis’s wartime radio talks about basic Christianity.

The book grew from a series of BBC radio broadcasts Lewis gave between 1941 and 1944. The talks were intended to explain shared Christian ideas in accessible language rather than defend one particular denomination.

Lewis organized the later book into four parts: “Right and Wrong as a Clue to the Meaning of the Universe,” “What Christians Believe,” “Christian Behaviour,” and “Beyond Personality.” The title refers to the common core of Christian belief, not to a separate denomination.

The radio talks were first published in separate books before being combined as Mere Christianity. Readers sometimes confuse it with The Problem of Pain, another major Lewis apologetic work, but that earlier book focuses specifically on suffering and divine goodness.