When Jesus taught in a synagogue, one of the men shouted out to him, asking him "Are you going to destroy the evil spirits?" Jesus didn't want the evil spirit to talk! He told the unclean spirit to be quiet and get out of that man.  Everyone was amazed when the man was violently shaken, and the spirit came out of him screaming! Nobody they knew could command unclean spirits. This was something new. Jesus had authority.