The Catechism in Questions & Answers

733. What is the significance of sacrifice in the new covenant?

The sacrificial service of the Old Testament, which was to reconcile human beings with God, lost its significance through the sacrifice of Christ (cf. Hebrews 8-10). In the sense of the New Testament, sacrifice implies leading a life in accordance with the gospel. So it is that Apostle Paul called upon the Christians to “present your bodies a living sacrifice, holy, acceptable to God” (Romans 12: 1).

New covenant: see explanation of Question 175.

“Now where there is remission of these [sins], there is no longer an offering for sin.”
Hebrews 10: 18