Many say we have no right to make a judgment of another person, we all make mistakes, and I agree in great part on that, but when God says that something is right or wrong, then that is not us judging & we better pay good attention. God’s Word is our final authority. We are not judging (condemning) people when we discern behavior or beliefs that are clearly unbiblical.
Unfortunately many Christians go to both extremes and some think they should not judge at all, they think Christianity means getting along with everybody. This fear of using proper judgment may come from a simple lack of understanding of God’s will. Some others go to the other extreme and judge the wrong way, looking to condemn or punish instead of looking to restore. But we shouldn’t judge according to our own perceptions, rather we should always judge according to the Word of God.
Judge not according to the appearance, but judge righteous judgment. John 7:24 (see Greek interlinear)
For what have I to do with judging those also who are outside? Do you not judge those who are inside? 13 But God judges those who are outside. Therefore “put away from among yourselves that wicked person. 1 Cor. 5:12-13