The commandment of rebuke (19:17) seems like an interesting instruction. Why would Hashem want us to reprimand each other? Should not each individual be responsible for their own lawfulness? Furthermore, is critique really going to create peace between people?
The reason this mitzvah might seem unreasonable is because of how we think of rebuke. Our tendency when we know something (even outside of the Torah) is to feel a certain level of ownership and autonomy over the truth. Leaving aside the fact that we most likely don’t know the full truth (certainly not enough to feel autonomous), we consider ourselves a gatekeeper of sorts. The truth, however, is that this commandment has nothing to do with self-righteous patronizing.
Let us imagine for the moment that someone lost a sum of money in a crowd. They’re upset and concerned, and after searching for a while they give up and return home. If someone were to knock on the door and return the money- how would you react? Surely, one wouldn’t feel insulted, condescended or parented. They would feel grateful, indebted, and relieved.
It is the same when we “rebuke” others. What we do is not because we’re trying to enforce Gd’s law- that’s not our responsibility. If we look at the its subsequent verse, we read: “Treat your fellow like yourself” (19:18). The purpose of “rebuke” is supposed to be another avenue of kindness towards others. It is as if he or she has “lost” an opportunity and our job is to help them find it- not because we know better, but because we want to help them find their better selves. If we view rebuke as a means of disseminating truth- then we’re doing it wrong. It is instead intended as the best type of kindness: the kindness of helping others grow.