I think we should all agree, that whatever conclusions one draws about the continuation of prophecy (or other gifts) today, whether in Old Testament or New, there was not necessarily a correlate between personal holiness and the ability to prophecy. I even think cessationists can use this argument against Roman Catholics.
In the Old Testament and in today’s history we see a number of people who were either temporarily immoral or reprobate accurately prophesying. I have in mind Balaam, Saul and others. Some were even good men who prophecied correctly but disobeyed God later and paid for it (the prophet who was killed by the lion; and even more troubling, the prophet who lied to him!).
I am currently reading Jack Deere’s Surprised by the Voice of God. Much of it is silly and dated, though there are a few important chapters. One troubling chapter is on Paul Cain. Cain, to whom I will not link, accurately prophecied numerous times beyond dispute (which forever buries the hard Princetonian case). As many know, Cain later fell into the most wicked of sins. Does that negate his previous accurate prophecies? I can’t imagine why, especially if we consider how many OT prophets either disobeyed God, were reprobate, or something like that–yet despite that they accurately prophecied.
This distinction can help cessationists because many will be confronted with miraculous claims by Orthodox and Romanist apologists. The older response was that these claims were simply fraudulent or demonic. While many in fact are, after a while such a denial begins to produce cognitive dissonance, which can be dangerous for some (and is one of the reasons that leads to the Convertskii).