In his book Mere Christianity, Lewis explains that men must make a decision about the person of Jesus:
One part of the claim tends to slip past us unnoticed because we have heard it so often that we no longer see what it amounts to. I mean the claim to forgive sins: any sins. Now unless the speaker is God, this is really preposterous as to be comic. We can all understand how a man forgives offenses against himself. You tread on my toes and I forgive you, you steal my money and I forgive you. But what should we make of a man, himself unrobbed and untrodden on, who announced that he forgave you for treading on other men’s toes and stealing other men’s money? Asinine fatuity is the kindest description we should give of his conduct. Yet this is what Jesus did. He told people that their sins were forgiven, and never waited to consult all the other people whom their sins had undoubtedly injured. He unhesitatingly behaved as if He was the party chiefly concerned, the person chiefly offended in all offenses. This makes sense only if He really was God whose laws are broken and whose love is wounded in every sin. In the mouth of any speaker who is not God, these words imply what I can only regard as a silliness and conceit unrivaled by any other character in history.
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 that 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 on 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.