Acts 19:13

"But" introduces a contrast to the good miracles that "God was performing . . . by . . . Paul" (Acts 19:11). As had been Peter’s experience, some of Paul’s observers tried to duplicate his miracles (cf. Acts 8:18-19). They wrongly concluded that the simple vocalization of Jesus’ name carried magical power. Some people feared the Jews in the ancient world because they thought the name of God, which the Jews refused to utter, was the key to their powers, including their success in business. This was Paul’s third contact with demonic powers that Luke recorded (cf. Acts 13:6-12; Acts 16:16-18).

"The use of magical names in incantations to exorcise evil spirits was common in the ancient world, and it seems to have been especially prominent at Ephesus." [Note: Longenecker, p. 497. See Bruce M. Metzger, "St. Paul and the Magicians," Princeton Seminary Bulletin 38 (1944):27-30.]

Earlier Jesus’ disciple John had asked Jesus to rebuke someone who was casting out demons in His name, and Jesus refused to do so. He replied, "Do not hinder him; for he who is not against you is for you" (Luke 9:49-50; cf. Mark 9:38-40). This incident exposed an attitude of rivalry among the Twelve that existed toward other disciples of Jesus. This was not a problem of orthodoxy; that exorcist believed in Jesus. It was rather a problem of fellowship or association; he was not one of the Twelve. He appears to have been on the fringe of Jesus’ followers. The Twelve wanted to exclude him, but Jesus wanted to include him. Jesus’ reply was proverbial. He had stated the reverse truth earlier (Matthew 12:30). Disciples should regard people who do not oppose them as associates rather than as enemies. The exorcists whom Paul encountered in Ephesus, however, appear to have been unbelievers.