The Magen David Series - Aveinu Malkenu
This prayer is chanted on the holiest day of the Jewish year, the Day of Atonement, Yom Kippur. Though Hashem is One, without separate parts, needs, or gender, we usually acknowledge G-d as male. This is to instill both love and fear of a father figure Who judges our actions, protects us, and enforces dicipline.
On Yom Kippur, we cry out to Our Father, Our King, to accept our repentance made on Rosh Hashanah, and inscribe us for one more year in the Book of Life.