The command "You shall rebuke" is preceded by the words "You shall not hate your brother," for this is a precondition for the rebuke.
The Torah continues, "...and you shall not ascribe sin to him," for if the rebuke was ineffectual, you are certainly the one responsible, for yours were not words coming from the heart.
I once had a Rav with whom I studied. One day he came over to me and said, "I'd like to learn the laws of rebuke with you." "Ok", I said, "when?". "Right now" he responded, and pulled a Shulchan Aruch (Code of Jewish Law book) and proceeded to learn the lessons of rebuke with me.
He then told me, "by the way, you've been doing such-and-such wrong, it's important you work to correct this deficient behavior." I asked him why he had learned with me first? He responded, "so both you and I can agree that I'm doing this the correct way, as I'm concerned about you and am concerned about whether you'll listen to my words."
One cannot rebuke out of anger or, G-d forbid, self concern, but out of love for one's fellow. Otherwise one's ego will get in the way of listening to the rebuke in defense of oneself.
Fix Israel's Leadership! Jewish Leadership Program - Click Here