"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
There is more good material in the latest chapter in his book, but this quote is well known, and if you hadn't heard it, I wanted you to. I've heard this misinterpreted by atheists before saying, "what about if he just didn't exist?" That is not the point of the quote. We can discuss historical reliability all day and you will find that the Christian has an embarrassment of riches in manuscript evidence. The point is that, from what we have about Him recorded, you must decide which of these He is. What will you decide about this man who claimed to be God Himself?