John Calvin Commentary Acts 19:13

"But certain also of the strolling Jews, exorcists, took upon them to name over them that had the evil spirits the name of the Lord Jesus, saying, I adjure you by Jesus whom Paul preacheth." — Acts 19:13 (ASV)

So that it may more plainly appear that Paul's apostleship was confirmed by those miracles which were recently mentioned, Luke now teaches that when certain people falsely pretended to use the name of Christ, such abuse was most sharply punished. From this we gather that such miracles were performed by Paul's hand for no other purpose than that all people might know that he faithfully preached Christ to be the power of God.

This is because the Lord not only prevented them from being separated from the pure doctrine of the gospel, but also so sharply punished those who absurdly drew them to their enchantments. From this we gather again, that whatever miracles darken the name of Christ are deceptive tricks of the devil. Furthermore, those who draw the true miracles of God to any other end, except that true religion may be established, are deceivers and falsifiers.

Certain exorcists. I do not doubt that this office proceeded from foolish emulation. God was accustomed to exercise His power in various ways among the Jews, and He had used the prophets in the past as ministers to drive away devils. Under this pretext, they invented conjuration, and as a result, an extraordinary function was rashly established without God's commandment.

Also, it may be that (God so appointing it) it had some effect; not that He favored it improperly, but so that they might more willingly retain the religion of their fathers until the coming of Christ. Under the reign of Christ, wicked ambition caused strife between the Christians and the Jews.

For exorcists were created according to human will. Afterwards (as superstition always grows worse and worse), the Pope wanted this to be common to all his clergy who were to be promoted to a higher rank. For after they are made doorkeepers, the conjuring of devils is immediately entrusted to them; and experience itself shows they make themselves ridiculous.

For they are forced to confess that they hold an empty title, one that is without effect—for where is the power they have to conjure devils? And the very exorcists themselves take upon themselves, to their own shame, an office which they never actually practice. But it justly happens that there is no end to erring when people depart from the word of God.

Concerning these men, we gather that they were wandering rogues, who went from door to door, of which kind we see many today in Popery; for he says that they went about. By these words, he gives us to understand that they went to and fro as opportunity arose for them to deceive people.

We adjure you by Jesus. It is probable that these deceivers resort to the name of Christ so that they might get new power, about which they had falsely boasted before, or because the power they had ceased, so that they might darken the gospel.

This invocation had two faults. First, since they were enemies of Paul’s doctrine, they abused its appearance without faith, as it were, for magical enchantments. Secondly, they took to themselves without God's calling that which is not in human power. But the lawful calling upon the name of God and Christ is that which is guided by faith and does not go beyond the limits of a person's calling.

Therefore, we are taught by this example that we must attempt nothing unless we have the light of God's word going before us, lest we suffer similar punishment for our sacrilege. The Lord Himself commands us to pray. Whoever does not have the gift of miracles given to them, let them keep themselves within these limits. For when the apostles made the unclean spirits come out of men, they had God as their authority, and they knew that they faithfully executed the ministry which He had entrusted to them.