Jesus I know, and Paul I recognize, but who are you?
In this story God does extraordinary, never before seen miracles through Paul, and because Paul also preached that God is no respecter of person and that He will do the same miracles through anyone that is willing, 7 sons of a priest went out and tried to do the same.
Once they tried to cast out an evil spirit though, the spirit only said that he knows Jesus and Paul, but not the 7. That is also why he was able to overpower them.
But now if God really is no respecter of person and if all the power is within the Name of Jesus, why did the brothers not manage to cast out the spirit?
The answer is found in verse 13. "I adjure you by the Jesus whom Paul proclaims!"
They couldn't cast the spirit out, because they did NOT have any revelation on the Name of Jesus themselves!
They heard all the revelations that Paul had, through which he did all those miracles and by which the devil knew him, but the brothers didn't have any revelation THEMSELVES.
It is good to listen to lots of preaching and to hear others revelation, BUT as long as you don't have a revelation on what you heard YOURSELF, it will bring NO fruit in your life.
It is also good to be willing, but before you go out and try to do great things for God, open His word and get yourself a revelation, directly from God himself. If you are willing to meditate on His word and open your heart to Him, He will for sure give you a revelation, and that revelation will then be worth more than everything else you heard!
Then, once you got that revelation, get ready for extraordinary, never before seen miracles, for the devil now knows your name.
You don't have to adjure him by the Jesus that Paul preaches, for NOW you can cast him out by the Jesus that lives IN you, that speaks to you and that you know personally!
With that Jesus, no evil spirit will try to wrestle with you, for the victory is already yours!
God is no respecter of persons and the same extraordinary miracles that God did through others, He will do through and in you, if you get the required revelation!
It is good to hear others preach, hear their revelation and see it in action, but that is not enough for you, because you cannot live off of their revelation. Once you heard it, go to the word and let God give you a first hand revelation on it, for you need your own revelation to see results! Only then can you go and live in authority, for now you don’t live by the Name of Jesus, that someone else preaches, but by the Name of Jesus, that you know personally and that YOU preach! (Acts 19,9-20)