What was the title of C.S. Lewis’s 1952 book of Christian apologetics based on BBC radio talks?

C.S. Lewis’s 1952 book of Christian apologetics based on BBC radio talks was Mere Christianity. The book developed ideas first presented in wartime broadcasts for the BBC, later revised and arranged into a single volume.

Lewis aimed to explain what he regarded as shared Christian beliefs rather than defend one denomination. The book is organized around a moral argument, Christian beliefs about God and humanity, and the practical implications of Christian faith. Its title refers to the common core Lewis believed united major Christian traditions.

The broadcasts were delivered during the Second World War, when religious programming reached a large British audience. Lewis’s clear, conversational style helped make abstract theological arguments accessible to general listeners. Mere Christianity later became one of his most widely read nonfiction books, though readers should distinguish it from The Problem of Pain, another major work of Lewis’s apologetics.