aut Deus aut malus homo

"aut Deus aut malus homo" is Latin for "Either God or a bad man"

In discussing his apologetic method, C. S. Lewis once stated that he usually found the aut Deus aut malus homo quite useful in demonstrating the validity of Christ's claims. (C. S. Lewis, "Christian Apologetics," in C. S. Lewis, God In the Dock, ed. Walter Hooper (Grand Rapids, Mich.: William B. Eerdmans Publishing Co., 1970), p. 101)

C.S. Lewis quotes:

"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." (C. S. Lewis, Mere Christianity (New York: Macmillan Co., Inc., 1943), pp. 55-56)

Lewis said there are three options:

1. Jesus was telling falsehoods and knew it, and so he was a liar.
   
2. Jesus was telling falsehoods but believed he was telling the truth, and so he was insane.
   
3. Jesus was telling the truth, and so he was divine.
   

"There is no half-way house and there is no parallel in other religions. If you had gone to Buddha and asked Him, "Are you the son of Bramah?" he would have said, "My son, you are still in the vale of illusion." If you had gone to Socrates and asked, "Are you Zeus?" he would have laughed at you. If you had gone to Mohammed and asked, "are you Allah?" he would first have rent his clothes and then cut you head off. If you had asked Confucius, "Are you Heaven?", I think he would have probably replied, "Remarks which are not in accordance with nature are in bad taste." The idea of a great moral teacher saying what Christ said is out of the question." (C. S. Lewis, "What Are We to Make of Jesus Christ?" in C. S. Lewis, God In The Dock, ed. Walter Hooper (Grand Rapids, Mich.: William B. Eerdmans Publishing Co., 1970), pp. 157-158)

Jesus said: "I am the way, the truth, and the life. No one comes to the Father except through Me" (John 14:6)

Jesus said: "He who has seen Me has seen the Father; so how can you say, ‘Show us the Father’?" (John 14:9)

Jesus asked: "Who do men say that I, the Son of Man, am?" (Matthew 16:13)

Jesus asks you! "But who do you say that I am?" (Matthew 16:15)

Liar, Lunatic, or Lord: you decide!

C.S. Lewis wikipedia