It is customary to (try to) forgive people who wronged you and ask others for forgiveness before Yom Kippur. Our actions “below” draw similar actions from “above”. But what does this mean — what is the point of forgiveness, whether between one human and another or between a human and G-d?
We forgive others because we realize that essentially we are one. One soul. One essence. And one cannot hate himself. (This, by the way, is the point of “loving your fellow as yourself”.)
The same is with G-d — we ask for His forgiveness, expect it and are granted it, because on Yom Kippur we reach the level where our essence is one with the Essence of G-d. There cannot be any separation, and, therefore, cannot be any grudges.
So, sins and offenses are not really “forgiven” — they simply loose their relevance, disintegrating in the unity of the offender and the offended, the soul and G-d.
G’mar chassima toivah!