The C.S. Lewis Trilemma

C. S. Lewis‘ so-called "Trilemma," or "Lord, liar, lunatic" argument challenges the watered-down opinions regarding the identity of Jesus as only a "great moral teacher" or a "prophet". The argument appears in Lewis’ book, "Mere Christianity". Here it is, in one paragraph:

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 the 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 patronizing nonsense about His being a great human teacher. He has not left that open to us. He did not intend to …. Now it seems to me obvious that He was neither a lunatic nor a fiend: and consequently, however strange or terrifying or unlikely it may seem, I have to accept the view that He was and is God.