Which C.S. Lewis book collects adapted radio talks on Christianity?

Mere Christianity collects C.S. Lewis’s adapted radio talks on Christianity.

The talks were broadcast by the BBC during the Second World War, beginning in 1941. Lewis spoke directly to a general audience rather than presenting a technical academic lecture series. He discussed morality, belief, Christian doctrine, and the reasons people might consider Christianity intellectually and spiritually credible.

The broadcasts were revised and published in book form as three sections: Broadcast Talks, Christian Behaviour, and Beyond Personality. The resulting volume appeared under the title Mere Christianity, which refers to the core beliefs shared across historic Christian traditions.

The book is an apologetic work, meaning it offers a reasoned defense or explanation of religious belief. It is not a complete statement of every denominational teaching, and Lewis did not intend it to settle all disputes between Christian churches. Its radio origin helps explain the conversational style that makes the book widely accessible.