Who is Jesus?
Was He just a great moral teacher?
Most people would admit that there was a man called Jesus but think that He was just a great moral teacher who died a tragic death and therefore we must give Him respect, but need give Him nothing more. However if we consider logically the claims that Jesus makes we can only have 3 possible conclusions. The first is that He was a fraud and knew He was a fraud, in which case He was a liar. The second is that He was fraud and didn't know it, which makes Him a complete lunatic. The only other option is that He was telling the truth, so He is Lord, and was completely true, therefore demanding that we do what He said. The idea that He was just a great moral teacher does not logically make sense.
In his book Mere Christianity, C.S. Lewis put it this way,
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 a man who says he is a poached egg - or he would be the devil of hell. You must take your choice. Either this was, and is, the Son of God, or else a madman or something worse. You can shut Him up for a fool 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.