What title did C.S. Lewis give his collection of wartime BBC talks on Christianity?

C.S. Lewis gave his collection of wartime BBC talks on Christianity the title Mere Christianity. The book developed from radio broadcasts delivered between 1941 and 1944 and collected material from several related publications.

Lewis designed the talks for a broad audience rather than for specialists in theology. He discussed moral law, Christian belief, and the central ideas shared across major Christian traditions. The broadcasts made his voice familiar to many listeners in Britain during World War II and helped establish him as a prominent Christian communicator.

The word “mere” does not mean unimportant. Lewis used it to indicate the basic or common core of Christian belief before disagreements among denominations. The final book is often confused with The Problem of Pain, an earlier apologetic work published in 1940, and with Christian Behaviour, one of the books that contributed to the radio-talk collection.