The Kol Nidre prayer is among one of the most solemn prayers in the Jewish machsor {prayer book}. It is always the very first prayer of the Yom Kippur service. Most shuls {including mine} usually get accomplished Chazzans/singers who can really express the feeling of this prayer.
The purpose of the Kol Nidre is to release us from our vows, vows made under duress, which we are unable to fulfill. Often we find ourselves making personal vows that we will abstain from foods, or drinks, and although we try we may fail to accomplish our goal. Hashem takes our vows seriously and when we have violated them we are liable to judgment. So what we do is absolve our vows publicly through this very deep prayer.
Chabad provides this insight into the Kol Nidre service...
http://www.chabad.org/holidays/JewishNewYear/template_cdo/aid/584901/jewish/Why-is-the-Kol-Nidre-so-holy.htmWhy is the Kol Nidre considered the holiest of Jewish prayers?
By Naftali SilberbergWhile the Kol Nidre – 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 Marannos (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 the Kol Nidre 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 Nidre prayer predates the Inquisition by at least 500 years. It would seem that the simple answer to the question is that the Kol Nidre 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, the Kol Nidre 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,
Chabad.org editorial team
