Jesus walked on the water, and he road in a boat as well. You read a book that deceived you into denying your faith. That is sad. Satan goes about as a roaring lion seeking whom he may devour. There is plenty of evidence that Jesus is Alive and still performing miracles today, through his Body, the church. There have been people raised from the dead, and creative miracles going on all around the world, and testimonies and documentation. The Creator of the Universe, Jesus Christ, can walk on water, or thin air if he wants. But the devil, through that book that you read, would have you believe, that he was just a good man, and not God. Well, hopefully, in the end, that good thing that was started in you will reach fruition, and you will again trust in Jesus as your Lord and Saviour.