"And the evil spirit answered and said [to the seven sons of Sceva], 'Jesus I know, and Paul I know; but who are you?' "
To me, this is one of the funnier verses in the NT. The demons were (of course) familiar with the Lord Jesus Christ, and even with the Apostle Paul--but they were not used to these "sons of Sceva." The end result was that the demon-possessed man beat them up (see v. 16). But there is a principle here: those who are not called to handle God's "sacred things" should not presume to do so.
This is not an "elitist" situation that God sets up in His church; but it is true that the Lord is a God of order, and that He has different roles and responsibilities for the dear souls that make up the body of Christ. Let us fulfill our duties diligently; and let us be genuinely grateful for our various callings.
[Puritan quote of the day: "We love to flatter our own affections, but this self-love is but self-hatred in the end." --Richard Sibbes, in, "The Soul's Conflict with Itself"]
