Catechism of the Catholic Church
2099 It is right to offer sacrifice to God as a sign of adoration and gratitude, supplication and communion: "Every action done so as to cling to God in communion of holiness, and thus achieve blessedness, is a true sacrifice." 16
2100 Outward sacrifice, to be genuine, must be the expression of spiritual sacrifice: "The sacrifice acceptable to God is a broken spirit...." 17 The prophets of the Old Covenant often denounced sacrifices that were not from the heart or not coupled with love of neighbor. 18 Jesus recalls the words of the prophet Hosea: "I desire mercy, and not sacrifice." 19 The only perfect sacrifice is the one that Christ offered on the cross as a total offering to the Father's love and for our salvation. 20 By uniting ourselves with his sacrifice we can make our lives a sacrifice to God.
English Translation of the Cathechism of the Catholic Church for the United States of America © 1997, United States Catholic Conference, Inc.