C.S. Lewis was asked by the BBC to give a series of talks on the radio during the second world war called “Mere Christianity”. These were later expanded into a book which is one of the best summaries of Christianity out there.
One of the most famous passages from this book is the following statement about who Jesus is. It is commonly known as “Lewis’ trilemma” or the “Mad, bad or God” argument. It is well worth reading this passage in context and, indeed, reading the whole book:
“Yet (and this is the strange, significant thing) even His enemies, when they read the Gospels, do not usually get the impression of silliness and conceit. Still less do unprejudiced readers. Christ says that He is ‘humble and meek’ and we believe Him; not noticing that, if He were merely a man, humility and meekness are the very last characteristics we could attribute to some of His sayings. I am trying here to prevent anyone saying the really foolish thing that people often say about Him: ‘I’m ready to accept Jesus as a great moral teacher, but I don’t accept His claim to be God.’ That is the one thing we must not say. A man who was merely a man and said the sort of things Jesus said would not be a great moral teacher. He would either be a lunatic—on a level with the man who says he is a poached egg—or else he would be the Devil of Hell. You must make your choice. Either this man was, and is, the Son of God: or else a madman or something worse. You can shut Him up for a fool, you can spit at Him and kill Him as a demon; or you can fall at His feet and call Him Lord and God. But let us not come with any patronising nonsense about His being a great human teacher. He has not left that open to us. He did not intend to.”
Lewis, C. S.. Mere Christianity (p. 24). HarperCollins Publishers. Kindle Edition.