“Will we judge fallen or unfallen angels (I Cor. 6:3), and how will we judge them? I understand that Christ is the judge.”
The reason Paul reminded the Corinthians that we will judge angels was to suggest that they should be able to settle disputes among believers (I Cor. 6:1-8). This implies that the angels we will judge are likewise unfallen. It is doubtful we’d be involved in judging fallen angels, or any beings, to eternal damnation.
The word judge has different meanings. Courtroom judges decide guilt or innocence and determine levels of punishment, while Olympic judges judge the performance of athletes and award them different degrees of reward. The Bible uses the word judge these ways, but in another way as well. The entire Book of Judges is all about the men who ruled over Israel. This is what the Lord meant when He told the twelve they would “sit upon twelve thrones, judging the tribes of Israel” (Matt. 19:28). We know that judge here also means to rule over since the Jews they will rule over will in turn rule “over” the cities of the world in the kingdom (Luke 19:17,19).
Psalm 82:1 said of God that “He judgeth among the gods,” i.e., the angels. While God will eventually condemn fallen angels to hell (Matt. 25:41), I Kings 22 shows how He judged among the angels in time past (vv. 19-22), and suggests how we will judge them in the ages to come. source