Jesus allows the demons to go into the pigs to show the entire area that he has power over demons, and in devotion to his Father, brings about the destruction of the unclean pigs. The single, powerful word of Jesus—”go”—shows the demons’ subjection to God’s sovereignty. The entry of the Spirit forces the departure of the demons (see also Matthew 12:28). In Jesus, God defeats Satan’s power.
It is striking that, despite the Jewish aversion to these animals, Jesus grants the demons their request to be cast into the herd of pigs. Apparently, he does so as a sign to the entire area that he, as Lord, advances against demons in the name of Israel’s God, who does away with pigs. The previously unassailable blockade of a highway melts before Jesus, and as the demon-possessed pigs drown, the presence of swine husbandry characteristic of Gentile life is removed by his actions. This inevitably creates a tension which draws the attention of all the people of the land to Jesus’ presence there.1
Still, in commanding them to go,
we clearly see here that the evil spirits do not have the power to do what they want and are fully subject to God’s sovereignty just as any other creature. As the Holy Spirit enters the men, the demons are forced to leave (see also Matthew 12:28).2 Satan himself is also fully subject to the authority of Jesus, not being able to do anything unless he grants it. God himself has subjected the devil to Jesus.3
32 And he said to them, “Go.” So they came out and went into the pigs, and behold, the whole herd rushed down the steep bank into the sea and drowned in the waters.