In his book Mere Christianity, C.S. Lewis addressed the inclination to say nice things about Jesus, but to stop short of calling him God.

He wrote, "I am here trying 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 that Jesus said would not be a great moral teacher. He would either be a lunatic—on a level with a 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 mad man 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 of that patronizing nonsense about his being a great human teacher. He has not left that open to us. Nor did he intend to."