“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.” 14 Seven sons of a Jewish high priest named Sceva were doing this. 15 But the evil spirit answered them, “Jesus I know, and Paul I recognize, but who are you?” 16 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 19:13-16 (ESV)
It’s always a gripping narration. The name of Jesus isn’t something to be taken lightly. Every time I read this I think of the disciples telling Jesus of the man casting out demons in his name, the man whom the disciples try stop because he isn’t one of them. (Luke 9:49 ff) At the time, Jesus tells them to let him continue because the one who is not against you is with you. But that is the thing with the sons of Sceva, they try to usurp the name while not trusting in Jesus, or being baptized or even listening to Paul. In all actuality they are against Jesus. So the demon beats them, and over powers them. But in this the sons of Sceva learn that the name of Christ is not something a person can just use, but it has to be given.