The Jewish Perspective on Judgment and Rebuke
The Torah gives us a commandment to rebuke someone who is committing an aveirah -- a sin -- as it says:
You shall not hate your brother in your heart. You shall surely rebuke your fellow, but you shall not bear a sin on his account (Leviticus 19:17).
While it is true that we should correct someone who is not properly living in accordance with Jewish law, it is vital to acknowledge that in the Oral Torah there are further instructions on how to do so. In fact, the immediately following verse (Leviticus 19:18) states:
You shall neither take revenge from nor bear a grudge against the members of your people; you shall love your neighbor as yourself. I am the Lord.
The reason that it states “[y]ou shall not bear a sin on his account” is to remind us that embarrassing another person is itself a sin; we must rebuke someone privately (Mesechet Rosh Hashana 16b and Yad, De'ot 6:7 [Rambam]). Yet the reasons that the Torah says we “shall surely rebuke” someone are simple.
We are prohibited from developing hatred for another person. By failing to correct someone and silently watching the person make mistakes, we begin to feel a certain level of resentment that grows over time; we have all felt frustration with this scenario.
A second reason for rebuking someone is just as simple, though possibly more difficult to internalize: By not correcting someone’s behavior, we are indirectly and partially responsible for his or her wrongdoing.
In Proverbs (9:8) we are told that we should only correct one who is likely to feel appreciation for you commenting on their actions. Otherwise, you may cause the person to feel resentment and hatred for you, which, as we’ve just mentioned, is a sin. For the same reason, it is therefore important that we work on accepting another’s rebuke of our own behavior with joy, and an eagerness to change (Talmud Yevamos 65b).