"But who are you?"

Then some of the itinerant Jewish exorcists undertook to invoke the name of the Lord Jesus over those who had evil spirits, saying, "I adjure you by the Jesus whom Paul proclaims." Seven sons of a Jewish high priest named Sceva were doing this. Acts 19:13-14

This is a classic warning to those who want miracles to beware! These guys didn’t know the Lord, they just wanted to be miracle workers.

But the evil spirit answered them, "Jesus I know, and Paul I recognize, but who are you?" Acts 19:15

And the demons called these false exorcists out, “Who are you!?”

And the man in whom was the evil spirit leaped on them, mastered all of them and overpowered them, so that they fled out of that house naked and wounded. Acts 19:16

The demons overpowered these frauds, beat them up, stripped them, and threw them out! Let this somewhat humorous episode be a warning not to usurp what God has not called and gifted us to do!