John Calvin Commentary Acts 19:16

"And the man in whom the evil spirit was leaped on them, and mastered both of them, and prevailed against them, so that they fled out of that house naked and wounded." — Acts 19:16 (ASV)

The man running upon them. What the devil did through him is attributed to the man. For he would not have been able to do such an act by himself, such as putting to flight seven strong young men, wounded and naked. And we cannot state with certainty how the devil dwells in men, except that there can be a contrariety between the Spirit of God and the spirit of Satan. For as Paul teaches that we are the temples of God, because the Spirit of God dwells in us, so he says again that Satan works effectively in all unbelievers. Nevertheless, we must know that Luke speaks in this place of a particular kind of dwelling: namely, when Satan has so much control that he possesses the whole man.

Furthermore, God intended to show such a sign, so that he might declare that his power is not contained in the sound of the voice, and that it is not lawful to superstitiously abuse the name of his Son. And when he allows Satan to deceive us, let us understand that we are more sharply punished than if he were to wound us in the flesh. For the false display and pretense of miracles is a horrible enchantment to bewitch and stupefy unbelievers, so that they may be drowned in deeper darkness, because they refused the light of God.