What does Acts 8:9 mean?

Few things are more despicable, spiritually, than when genuine seekers are deceived by frauds. Ever since the northern kingdom of Israel was established, the people of Samaria have been pushed away from legitimate worship in Jerusalem and toward idolatry (1 Kings 12:25–33). Jesus promised the Samaritan woman at the well that her people would soon be welcome to worship God properly in their own land (John 4:20–24). But before that time comes, an imposter moves in. This person doesn't just say or believe wrong things, he actively tells other people they should see him as "great."

We're not told who Simon is—whether he's a Jew, a Samaritan, or some other nationality. We do know that some Gentiles are so intrigued by the Jewish culture that hucksters sometimes defrauded the people, claiming to be from God but using power from a demonic source. This was similarly the case with Bar-Jesus, also known as Elymas, whom Paul and Barnabas will meet on Cyprus (Acts 13:4–12) and possibly the sons of Sceva in Corinth (Acts 19:11–16). Such trickery was not a new practice, we even see it in the time of Judges when a man named Micah convinced a Levite to be his personal priest (Judges 17).

It's important to remember that all supernatural power comes from one of two sources: God or demons. There is no such thing as "white" magic; every supernatural ability or event not of God is evil. The people of Corinth realize this when the evil spirits throw the sons of Sceva out of the house, naked and wounded. Presented with Paul's Holy Spirit-empowered miracles and the stripped and wounded Jewish exorcists, the people surrender their books of divination, worth 50,000 pieces of silver, and gladly watch them burn (Acts 19:17–20).