9 Now a certain man named Simon had previously practiced magic in the city and amazed the people of Samaria, saying that he was someone great. 10 All of them, from the least to the greatest, listened to him eagerly, saying, "This man is the power of God that is called Great." 11 And they listened eagerly to him because for a long time he had amazed them with his magic. 12 But when they believed Philip, who was proclaiming the good news about the kingdom of God and the name of Jesus Christ, they were baptized, both men and women. 13 Even Simon himself believed. After being baptized, he stayed constantly with Philip and was amazed when he saw the signs and great miracles that took place.
Matthew Henry's Commentary on Acts 8:9-13
Commentary on Acts 8:5-13
(Read Acts 8:5-13)
As far as the gospel prevails, evil spirits are dislodged, particularly unclean spirits. All inclinations to the lusts of the flesh which war against the soul are such. Distempers are here named, the most difficult to be cured by the course of nature, and most expressive of the disease of sin. Pride, ambition, and desire after grandeur have always caused abundance of mischief, both to the world and to the church. The people said of Simon, This man is the great power of God. See how ignorant and thoughtless people mistake. But how strong is the power of Divine grace, by which they were brought to Christ, who is Truth itself! The people not only gave heed to what Philip said, but were fully convinced that it was of God, and not of men, and gave up themselves to be directed thereby. Even bad men, and those whose hearts still go after covetousness, may come before God as his people come, and for a time continue with them. And many wonder at the proofs of Divine truths, who never experience their power. The gospel preached may have a common operation upon a soul, where it never produced inward holiness. All are not savingly converted who profess to believe the gospel.