Repentance (teshuva) is the theme of Yom Kippur. While our sins alienate us from God, our repentance reconciles us with God. On Yom Kippur, we ask for God to forgive us for our sins.
The first Yom Kippur occurred when Moses descended Mount Sinai with the second set of Tablets, a symbol of the renegotiated covenant between God and the Jewish People. The Israelites alienated God by worshipping the golden calf. Moses ascended Mount Sinai to ask God for forgiveness. The Israelites repented by fasting during the day while Moses was on the mountain. On the tenth day of the Hebrew month of Tishrei (Yom Kippur), Moses descended Mount Sinai with the second Tablets.
God decreed the tenth day of the month of Tishrei as a day of atonement:
"Let it be a statute for you forever: in the seventh month, on the tenth of the month, you shall starve your vital energies and do no manner of work.... For on this day it shall bring atonement upon you, to purify you, before God shall you become pure of all your aberrations." (Vayikra/Leviticus 16: 29-30)
Just as the Israelites alienated God with their unfaithful behavior, some of our behavior during the year has also alienated us from God. Just as the Israelites repented for their sins, we also repent for our sins. If the main reason for our sins is our quest for physical gratification, the way to atone for our sins is to elevate ourselves above the physical and into the spiritual realm. Praying, fasting, and abstaining from work and physical pleasures, enables us to envision the divine image that lives in each of us, denounce our bad deeds, and aim to do good deeds. Just as God forgave the Israelites on the tenth of Tishrei, it is our hope that God will forgive us on Yom Kippur.
The Israelites were able to go from the depth of worshipping a golden calf to the heights of receiving the Torah. We believe God is merciful. We hope that if we repent for our sins, then God will forgive us and grant us a good signing (chatima tova) in the Book of Life.
