What does Acts 19:19 mean?

The people of Ephesus are learning what real supernatural power looks like. Like all pagans in the Roman Empire, they have household idols and city gods; they are known for the temple of Artemis. They also have a culture of witchcraft, which attracts demons, which attract Jewish exorcists.

This is the state of the city when Paul arrives. In response to all the magic, the Holy Spirit empowers him to heal and expel demons in Jesus' name. Jewish magicians hear him and start using "Jesus" as a kind of magical word. When seven sons of a Jewish high priest named Sceva enter a house and try to use Jesus' name to expel a powerful demon, the evil spirit attacks them, and the would-be exorcists run out in the street (Acts 19:11–16).

The whole city hears, and many of the practitioners of witchcraft immediately respond. Likely, they realize their spells and incantations don't really control demons, but Paul does. First, they reveal their practices, thus voiding them of power (Acts 19:17–18). Now, they burn their spells. "Ephesian writing," or Ephesia grammata, is a reference to written-down spells, some rolled into small containers and worn as amulets. If the pieces of silver are silver drachma, the value would be something close to 150 years' worth of a laborer's wages.

It's not uncommon for an unbeliever to see the power of Jesus and want to use it to gain influence and money. Simon the Magician did so in Samaria (Acts 8:9–24). But sometimes people are just waiting for rescue. When criticized for eating with unsavory people, Jesus said He came for the sick who need a doctor (Mark 2:15–17). When Zacchaeus heard Jesus, he gratefully accepted Jesus' message and His love and resolved to return what he had cheated (Luke 19:1–10). As Paul works, the demons flee left and right (Acts 19:12). Maybe the magicians just need someone to rescue them.