Review these prays. Reflect on them. Then examine your heart asking God to illuminate your mind to areas that you need forgiveness for sin, idols you have before God, and attitudes that need to be changed. Then, ask God to transform your heart by the power of the Holy Spirit. Surrender to any changes that God wants to make in your life.
Penitential Prayer of St. Ambrose of Milan:
O Lord, who hast mercy upon all, take away from me my sins, and mercifully kindle in me the fire of thy Holy Spirit. Take away from me the heart of stone, and give me a heart of flesh, a heart to love and adore Thee, a heart to delight in Thee, to follow and enjoy Thee, for Christ's sake, Amen.
Penitential Prayer of St. Augustine:
O Lord, The house of my soul is narrow; enlarge it that you may enter in. It is ruinous, O repair it! It displeases Your sight. I confess it, I know. But who shall cleanse it, to whom shall I cry but to you? Cleanse me from my secret faults, O Lord, and spare Your servant from strange sins. Amen.