Teshuvah, tefillah, and tzedakah -- translated respectively as repentance, prayer and charity -- are key tenets of Rosh Hashanah and Yom Kippur liturgies in Jewish culture.
This is an ancient prayer reminding us not only of our fallen natures, but the need to live a life inspired by the Torah including acts of humble kindness, benevolence, and goodwill to our fellow men. It is a time of reflection on where we have been in the past year and what we want to change going forward; it is also a chance to repent and cleanse ourselves of any known or cherished sins for the year ahead.
Ideally, these prayers should not be limited to just the High Holy Day season, but should be prayed throughout the year.