Now a large herd of swine was feeding there on the hillside.And they pleaded with him, Send us into the swine. Let us enter them.”And he let them, and the unclean spirits came out and entered the swine. The herd of about two thousand rushed down a steep bank into the sea, where they were drowned. The swineherds ran away and reported the incident in the town and throughout the countryside .And people came out to see what had happened. As they approached Jesus, they caught sight of the man who had been possessed by Legion, sitting there clothed and in his right mind. And they were seized with fear. Those who witnessed the incident explained to them what had happened to the possessed man and to the swine. Then they began to beg him to leave their district. As he was getting into the boat, the man who had been possessed pleaded to remain with him. But Jesus would not permit him but told him instead, “Go home to your family and announce to them all that the Lord in his pity has done for you.” Then the man went off and began to proclaim in the Decapolis what Jesus had done for him; and all were amazed." Mark 5:1-20
Having just read the entire Gospel of Mark and Mary Healy's excellent commentary on it, I though I would give my 2 cents worth. Mark is very detailed in describing this wild, crazy guy who even chains can't hold. He's naked and scaring the hell out of anybody who comes near. Yet the demon readily recognizes Jesus “What have you to do with me, Jesus, Son of the Most High God? As we all know, fear of the Lord is the beginning of wisdom. Demons easily recognize Him but wise men and women in the 21st century can't. Oh, the demon tries to put on a show when he was asked what his name was, puffing himself up with the name Legion, but Jesus is not impressed. The point that I take from this passage is sometimes we have to kick evil in the butt. Sometimes we are going to have to do battle with evil spirits in order to stay on the path to salvation. We have the power and authority in Jesus Christ whose words have command over them.