A central legend during the observance of Yom Kippur is that of the Book of Life.
According to the legend, God judges us during the 10 days between Rosh Hashanah and Yom Kippur, called the "Days of Awe."
Those who truly repent and atone for their sins get to have their names written down in the Book of Life for a positive year; those who have not sufficiently repented do not.
We are told repeatedly in the Yom Kippur liturgy that "repentance, prayer and acts of charity (teshuvah, tefillah and tzedakah) overturn the evil decree."
According to tradition, the only sins that God automatically forgives on Yom Kippur are those committed against God.
Sins against other people can only be forgiven if we attempt to make amends directly to the ones we wronged over the course of the past year.
Tradition teaches us that it is not enough to regret our mistakes; we must take steps to correct them. First, we need to declare that we regret our actions. Next, we must make amends, such as apologizing to any injured parties or paying damages for items that have been broken, either purposely or by accident.
Only then are we free to stand before God and ask for forgiveness.
In Jewish tradition, the word that is generally translated to mean "sin" actually means "missing the mark." And that's a big difference. It means that errors aren't permanent; they're simply mistakes, and all humans make them.
Judaism permits us to learn lessons through trial and error. The point is to have a target or a spiritual direction to guide you.