C.S. Lewis published Mere Christianity in 1952.
The book developed from a series of BBC radio talks Lewis delivered during World War II. The talks were broadcast in three groups between 1941 and 1944, and Lewis later revised and combined material from them into a book. Geoffrey Bles published Mere Christianity in 1952.
The title refers to the shared core of Christian belief rather than to one denomination. Lewis discusses morality, Christian doctrine, and the meaning of Christian conduct in language intended for a broad audience. A common mix-up is to date the book to 1941, the year of the first broadcasts; 1952 is the publication year of the consolidated volume, while the radio talks came earlier.