Why did a demon refuse to leave when the sons of Sceva commanded it to leave in the name of Jesus?

ANSWER

The demon said he did not know them

Acts 19 :

(1) Some Jews who went around driving out evil spirits tried to invoke the name of the Lord Jesus over those who were demon-possessed. They would say, “In the name of the Jesus whom Paul preaches, I command you to come out.” (14) Seven sons of Sceva, a Jewish chief priest, were doing this. (15) One day the evil spirit answered them, “Jesus I know, and Paul I know about, but who are you?” (16) Then the man who had the evil spirit jumped on them and overpowered them all. He gave them such a beating that they ran out of the house naked and bleeding.
Play Our Bible Trivia Game
Can You Light All 30 Candles?