For Rabbi Stern, fasting on Yom Kippur is sociological and familial. He does it because the people around him are doing it. That may be enough of a reason for him, but it is certainly not for me.

I fast because the Torah tells us to afflict ourselves on Yom Kippur and as far back as we can tell, Jews have understood that to mean fasting.

I fast because it reminds me that I have greater control over myself than I usually give myself credit for. Each year I am reminded that if I can make it through 25 hours of fasting, I also have it within my power to overcome other driving elemental urges, like eating too much chocolate or snapping at my son when I have had a tough day and he is being a teenager.

I fast because it reminds me to be grateful that this fast is by my choice; that I am alive now, and not in 1940s Europe; that I live here in America, and not in Darfur. I express my gratefulness to God, through my fast and by writing checks to Mazon and bringing food to my synagogue’s annual Operation Isaiah food collection.

Finally, I fast because it connects me to the Holy and makes the day Holy.

Rabbi Hayim Kieval, in his book The High Holy Days, suggests that for us to consider something truly “holy,” we must be willing to make the ultimate sacrifice for it. He is writing about why the story of Abraham being willing to sacrifice his son Isaac (known in Hebrew as the Akedah) is read on Rosh Hashanah. But his observation is appropriate for Yom Kippur and offers another insight into why I fast: Fasting on Yom Kippur provides the opportunity to experience the holy.

Holiness is not something we can pick up on eBay. We can only attain it through personal sacrifice.

Personal sacrifice does not mean suffering. It means self-control and generosity of spirit. The sacrifice of fasting on Yom Kippur provides us a taste (excuse the pun) of what holiness can feel like.

For most of us, that sacrifice is neither great nor insurmountable. (Jewish law obligates the sick to follow doctor’s orders about eating and taking medications.) Nevertheless, fasting can transport us to another place spiritually–a place in which we can find absolution, wholeness, and a sense of closeness to God.