Most of us are familiar with the Talmudic teaching that God does not forgive us for our interpersonal sins on Yom Kippur unless we are forgiven by those we have wronged. Rabbi Yehudah Aryeh Leib of Gur, author of the Hasidic commentary Sefat Emet, explains the conceptual basis for this passage. The purpose of Yom Kippur is to restore unity that has been broken in the previous year. This theme means that we must repair two sets of relationships, those between us and God, and those between us and our friends. Our sins sever our inherent union with God, while our disagreements with those around us dissolve our commonalities. Just as Yom Kippur calls upon us to mend our relationship with God, the motif of unity requires us to repair our relationships with our friends.