Proverbs 14:7 tells us what we can do in such a case—it says, “Go from the presence of a foolish man, when you do not perceive in him the lips of knowledge.”
Biblically, a fool is not someone of low human intelligence, but someone who makes ungodly choices. A man could be wicked smart, as they say, but if he walks contrary to God’s way, God classifies him as a fool. So, Proverbs 14 says to leave the presence of a fool when we perceive he does not have true knowledge. When we add in God’s prescription that a false prophet be put to death, even though we don’t carry that out, we can reckon that prophet as dead to us. There is no point in paying him any heed.