Mark 5:8–17(NKJV)
8 For He said to him, “Come out of the man, unclean spirit!” 9 Then He asked him, “What is your name?” And he answered, saying, “My name is Legion; for we are many.” 10 Also he begged Him earnestly that He would not send them out of the country.11 Now a large herd of swine was feeding there near the mountains. 12 So all the demons begged Him, saying, “Send us to the swine, that we may enter them.” 13 And at once Jesus gave them permission. Then the unclean spirits went out and entered the swine (there were about two thousand); and the herd ran violently down the steep place into the sea, and drowned in the sea.14 So those who fed the swine fled, and they told it in the city and in the country. And they went out to see what it was that had happened. 15 Then they came to Jesus, and saw the one who had been demon-possessed and had the legion, sitting and clothed and in his right mind. And they were afraid. 16 And those who saw it told them how it happened to him who had been demon-possessed, and about the swine. 17 Then they began to plead with Him to depart from their region.
I suppose no one in the faith is surprised that demonic forces are subject to Christ, and would bow down before Him, seeing that He is God. And they beg Him not to send them out of the country. What was so wonderful about the country of the Gadarenes? Nothing for the people of the area, but, definitely fertile ground for demonic influence. They would rather inhabit a herd of pigs, than to be out of work so to speak.
Some have speculated that these demons tricked Jesus by ruining His opportunity to stay and preach in the country, but I think that they themselves were tricked, and I truly know, that no demon is more wise than Christ. In the last section, I said that the demoniac was able, even under such possession and oppression, to come to Jesus by his own volition. Do not the swine have the same ability? Yes, the legion of demons was permitted by Jesus to move into the herd of swine (about 2000), but the demons could never have known that this herd would run violently into the water and drown themselves, also providing no rest for the legion. But Jesus would, since He knew all things. If we think for a moment that the Lord had pity on demons, we are not thinking clearly. Their demise was already set and there was never and never will be any provision for redemption for any of them. The demise of their place of rest, was just and good. The death of all those animals, though they were unclean animals by Jewish law, was and always is troubling to God, but this is not His fault, but the result of the sin of mankind. Now there is a lesson here we must keep in mind; not every miracle will be accepted by a sinful society, especially when it disrupts their profit margin. They protect what they have even if what they have leads them to spiritual death.