The Bible says that the Devil used a snake to tempt Eve into eating fruit from the Tree of Knowledge of Good and Evil, which was the only thing that God told her not to do. For this reason, Christians believe that snakes are evil creatures. I, on the other hand, do not believe that because the Devil used a snake to tempt Eve, does not mean that the snake is evil. It just means that the Devil is evil, and happened to use a snake to do his bidding.