Unfortunately, many people don't believe that the Devil really exists. Once there was a boxer who was being badly beaten. The Trainer said, Oh, no he s not. He s not even hitting you. At that point the boxer wiped the blood away from his eye and said, Well, then, I wish you d watch that referee.
Some people are like that trainer, they deny the obvious.
Jesus sure did. On one occasion Jesus said, Every kingdom divided against itself will be ruined, and every city or household divided against itself will not stand. If Satan drives out Satan, he is divided against himself. So then, they will be your judges. First, Jesus believed in them.