While Kol Nidrei—a prayer wherein we release vows—is certainly traditionally seen as one of the most important prayers of the year, there is little in Jewish literature to support this idea.
The question, however, remains: why does Jewish tradition lend so much weight and solemnity to this seemingly technical prayer?
There are those who have claimed that the reason goes back to the days of the Spanish Inquisition, when the conversos (Jews who chose to convert to Christianity rather than face expulsion or death, but remained faithful to Judaism at heart, and to some degree in observance too) would gather on Yom Kippur eve in their hideout synagogues. Before beginning the Yom Kippur services, they would tearfully and emotionally entreat G‑d to forgive them for all the public statements they made in the previous year which were contrary to Jewish doctrine. This is supposedly also the reason why Kol Nidrei is prefaced with the statement: “. . . by the authority of the heavenly tribunal and by the authority of the earthly tribunal, we hereby grant permission to pray with those who have transgressed.”
While this is certainly a romantic answer, the fact is that the Kol Nidrei prayer predates the Inquisition by at least 500 years. It would seem that the simple answer to the question is that Kol Nidrei is the opening prayer of the holiest day of the year, and as such is said with great devotion—not because of its content.
According to Kabbalah, Kol Nidrei is more than a technical vow-annulment procedure. Rather, by releasing our vows we are asking G‑d to reciprocate in kind. In the event that He has pledged not to bring the redemption just yet, in the event that He made an oath to bring harsh judgments on His people in the following year, we ask that He release these vows and instead grant us a year of happiness and redemption.
Perhaps this is the reason for the solemnity of the prayer.
Have a sweet and healthy new year,
Rabbi Naftali Silberberg,
for the Chabad.org editorial team