This is new content in the second edition of Praying the Mass: The Prayers of the People, Chapter 9, "Offertory Prayers".
St. Peter Chrysologus ended his sermon with a challenge to live as self-sacrificing priests. First, he spoke of the preparation necessary:
Each of us is called to be both a sacrifice to God and his priest. Do not forfeit what divine authority confers on you. Put on the garment of holiness, gird yourself with the belt of chastity. Let Christ be your helmet, let the cross on your forehead be your unfailing protection. Your breastplate should be the knowledge of God that he himself has given you. Keep burning continually the sweet smelling incense of prayer. Take up the sword of the Spirit. Let your heart be an altar.
Once you are prepared, spiritually clothed in priestly attire and standing at the altar of your heart, ready to serve the Lord, then:
with full confidence in God, present your body for sacrifice. God desires not death, but faith; God thirsts not for blood, but for self-surrender; God is appeased not by slaughter, but by the offering of your free will.
This is the spiritual attitude we must strive to adopt in our daily lives, but especially during the