Luke 8:26 And they arrived at the country of the Gadarenes, which is over against Galilee.
Gadarenes was on the opposite shore from Galilee. Jesus has arrived where satan has had his way.
Luke 8:27 And when he went forth to land, there met him out of the city a certain man, which had devils long time, and ware no clothes, neither abode in any house, but in the tombs.
A wretched, demon possessed naked man met them; his dwelling place was the tombs. Where the bad spirits dwell there is death and misery.
Luke 8:28 When he saw Jesus, he cried out, and fell down before him, and with a loud voice said, What have I to do with thee, Jesus, thou Son of God most high? I beseech thee, torment me not.
Well, this is interesting. The devils in the man knew who Jesus was; the Son of God most high. They were in the spirit world and recognized Jesus as the Lord of hosts, the Son of God. The bad spirits were cowards before God, they tormented the man without mercy, but now they cower before Jesus saying what have you to do with me, do not torment me.
Luke 8:29 (For he had commanded the unclean spirit to come out of the man. For oftentimes it had caught him: and he was kept bound with chains and in fetters; and he brake the bands, and was driven of the devil into the wilderness.)
Mark 5:5 And always, night and day, he was in the mountains, and in the tombs, crying, and cutting himself with stones.
What a mess this man was, but there are others in a mess today, cutting themselves as did this demon controlled man. What happens when bad spirits enter? Cutting, uncontrolled rage, "bad angel" strength, how often have we heard people speak against God as though he would restrict their freedom? Well, this man could not be restrained even with ropes and chains, but he was not free. What a miserable creature he was. True freedom is of God's Spirit. Jesus spoke to the devils to come out.
Luke 8:30 And Jesus asked him, saying, What is thy name? And he said, Legion: because many devils were entered into him. Many, many bad spirits were in this man.
Luke 8:31 And they besought him that he would not command them to go out into the deep. They begged Jesus that he would not command them to go into the deep.
The deep? The pit of hell, restrained until the Judgment Day. These spirits could not die, but they could be cast into hell, not by a mere man, but by God. Jesus is the very power and image of God. A note here. Some like to use the power of Jesus to cast out devils. This can become hocus pocus, or presumption. If you have sin in your life the demons will not be moved. We are not to be looking for devils to cast out. Some claim to be prophets, yet they do not live as prophets, sin follows them. The power of God is available in the believer and at the Lord's command the devils can be cast out. It is not something to play with as a new thrilling game. It takes fasting and prayer. You should not go around as "Wanda the witch," performing magic tricks.
Jesus explain this to his disciples, at another encounter
Mark 9:25 When Jesus saw that the people came running together, he rebuked the foul spirit, saying unto him, Thou dumb and deaf spirit, I charge thee, come out of him, and enter no more into him. This is important, to say enter no more into him.
Mark 9:26 And the spirit cried, and rent him sore, and came out of him: and he was as one dead; insomuch that many said, He is dead.
Mark 9:27 But Jesus took him by the hand, and lifted him up; and he arose.
Mark 9:28 And when he was come into the house, his disciples asked him privately, Why could not we cast him out?
Mark 9:29 And he said unto them, This kind can come forth by nothing, but by prayer and fasting.
It is not the work of the flesh, but of the Spirit of God.
Isa 61:1 The spirit of the Lord GOD is upon me; because the LORD hath anointed me to preach good tidings unto the meek; he hath sent me to bind up the brokenhearted, to proclaim liberty to the captives, and the opening of the prison to them that are bound;