At the celebration of the Holy Sacrifice of the Mass, we begin with the call to repentance and to a reflective manner of life is issued in what is called the Penitential Rite. The most common form of this rite is what we call the Confiteor or the I Confess. The Confiteor is the traditional formula for confessing our sins in which we acknowledge sins of commission and sins of omission; and in which we also call upon Our Lady the Mother of mercy and the angels and the saints to intercede on our behalf in our struggle with sin.