We can judge our neighbor’s actions but not his intentions, which are known only to him and God (unless the person makes an evil intention known); and we can not judge a person’s heart, only his external behaviors. Thus, we can judge that our neighbor’s behavior is evil, but we can not say that our neighbor himself is evil (because we do not know his heart - this is known to God alone). Jesus tells us not to judge (judge rashly), as only He (God) can read what is in a man’s heart who objectively sins. Jesus’ own words: “Judge not, lest you be judged.” Giving fraternal correction is not considered rash judgement, but it is a spiritual act of mercy. Rash judgement is the evil Jesus speaks of when he tells us not to judge. Rash judgement is judging your neighbor to be evil and/or condemned to hell - being judgemental is condemnatory. Who knows who is definitely going to hell? only God knows, no matter how black and white it may appear to people. God can judge men’s hearts - we can’t (except maybe a few Saints could). Those in lawful authority can lawfully judge a person’s behaviors as being worthy of correction/punishment, as long as they remain impartial.