And God wrought special miracles by the hands of Paul:
So that from his body were brought unto the sick handkerchiefs or aprons, and the diseases departed from them, and the evil spirits went out of them.
Then certain of the vagabond Jews, exorcists, took upon them to call over them those who had evil spirits the name of the Lord Jesus, saying, We adjure you by Jesus whom Paul preaches.
And there were seven sons of one Sceva, a Jew, and chief of the priests, which did so.
And the evil spirit answered and said, Jesus I know, and Paul I know; but who are you?
And the man in whom the evil spirit was leaped on them, and overcame them, and prevailed against them, so that they fled out of that house naked and wounded.
And this was known to all the Jews and Greeks also dwelling at Ephesus; and fear fell on them all, and the name of the Lord Jesus was magnified. Acts 19:12-17.
This story gives us insight into some of the ways evil spirits operate. Notice in the passage that the evil spirits knew who Paul was. Of course, they knew who Jesus was, but they didn't know who these 'sons of Sceva' were, and they were successful in wounding them.
What about us? Do you think the evil spirits know who you are? They will know exactly who you are, if you are in Christ. Evil spirits know who those human beings are, who belong to God. They don't know those who don't know the Lord though, and they will prevail over them.
If you have a relationship with the Lord Jesus Christ through His death on the Cross, then the evil spirits know you. It is an honor to be known to those in the Dark World. If you are in Christ, the Bible says that you have authority over all the power of the Enemy, and the evil spirits do not want you to know that, nor do they want you to use your authority over them.
The reason that the sons of Sceva were wounded was that they didn't have a relationship with the True and Living God. They were still in the kingdom of Darkness. They tried to use God's power, without having a proper relationship with God. They got hurt.
If you are a believer in Jesus Christ, and you are trusting in His Cross to pay for your sins, you have authority over the evil spirits and do not have to be afraid of them (but you have to use the authority over them). If you do not know the Lord Jesus Christ yet, please consider what He has done for you on the Cross. If you would like more information on how to come to the Lord Jesus Christ and trust in Him as the atonement for your sins, please go to http://thegospelconversation.blogspot.com or http://test4gp.wordpress.com
This issue could not be more serious.