Yom Kippur is as old as the Bible and as modern as apologizing to our friends. On this “Day of Atonement,” Jews repent for mean words, grudges and other acts of “causeless hatred” — the ones we all commit, though we strive not to. Judaism asks that we seek forgiveness first from those we have harmed. Only when we forgive each other can God forgive us. Then, we pray that in “abundant compassion,” God will “erase all records of our guilt,” inscribing us in the Book of Life for a year of “good life and peace.”

In turning with naked honesty to friends and to God, we also turn toward ourselves. We search our souls. We wonder if we are the people we want to be, leading lives we wish to lead. Yale’s frenzy of classes and meetings leaves us time to answer nearly every question but this one. The quiet of Yom Kippur gives us one last chance to change our lives, to repair ourselves. When the sun sets, ending the holiday, God seals the Book of Life. We return through dusk to dorm rooms and mountains of reading. The year begins again.

Nothing expresses this spirit better — or more enigmatically — than “Kol Nidre,” the opening prayer of Yom Kippur Eve. “Kol Nidre,” or “All Vows,” declares: “All vows we swear for the New Year are null and void … Our vows shall not be valid.”

Canceling our promises before we even make them seems strange. Imagine this scenario: You assure your parents that this year, you will get better grades and call home more often. You ask your significant other how you could treat her (or him) better, swearing to follow through. Then, you add, “Oh, and if I break these promises, they never counted anyway.”

Such bet-hedging would undermine your word, no? You might even think it would be dishonest. And it would be, except we cannot keep a vow never to sin. As parents, children, girlfriends, roommates — we all make unfortunate mistakes.

That is the insight of “Kol Nidre.” We are not demi-angels in easy reach of perfection, but this flaw does not make us sinners to be written out of the Book entirely. We are in between. We are human.

God, who has seen it all before, offers us a safety net. Should we break our contract not to sin, we are forgiven in advance.

Judaism does not hold humans to unreasonable expectations. But it does suggest that forgiveness is a two-way street. Returning to our analogy, imagine thinking: “Let’s party! I’ll mess up, and be forgiven, whether I try to be good or not. I’m off the hook.” That is where Judaism draws the line. Imperfection, despite best efforts, is one thing. Indifference is another. It may be that “our vows are not valid.” Still, we spend an entire day fasting, meditating and praying to make them.

We have failed, at times, to keep our promises. We will fail again. But to be forgiven when we do, we must strive to keep them, truly believing that this year, we will succeed.

Judaism’s notion of repentance reminds me of the Red Sox. (I suppose it works for the Cubs too, but I grew up in Boston.) From 1918 to 2004, Boston’s boys never won a World Series. Not only that: They kept coming close. Every autumn brought an innovative new way to break Bostonians’ hearts.

Yet each year, Sox fans flocked to games. “This is the year,” they shouted. This year, things would be different. This year, what stood in the way would step aside.

It was unlikely to be “the year,” whispered a piece of each fan’s heart — but not the bigger piece. Sox fans stayed for each tense ninth inning and each tenser 10th. They held signs that read, “I Believe.” In crowded, paint-chipped Fenway Park, they stood and shrieked, as their fervent Puritan forbears had done in austere meetinghouses four centuries before.

Every October, it turned out not to be “the year.” But Boston’s losses took on a nobility, a piety, part of something far vaster than baseball. To live in Boston in 2004 was to taste the end of a history of existential striving.

Would that life were as elegant as baseball. Every year, we vow that this is the year when we will make no mistakes. We will never lose our temper with our families; we will never gossip; we will never say things we do not mean. Every year — at least once — we end up shouting at parents and siblings, making fun of someone behind his back and making a stupid, hurtful comment that has us kicking ourselves.

Yom Kippur comes again. With it comes our apology for the same things as last year. A piece of our hearts knows we will come back to synagogue to apologize for the same things next year. It is a piece of our hearts — but not the bigger piece.

Noah Lawrence is a sophomore in Saybrook College.