Today’s second reading from the Letter to the Hebrews uses language describing the priesthood of the Old Testament and the offering of animal sacrifices. God taught his people over the course of centuries that sin required sacrifice to make atonement. The priests of the Old Testament offered various sacrifices including animals in atonement for sins. The problem with these sacrifices was that the priests offering them were themselves sinners and the animals weren’t really capable of taking away sins.

In the New Testament, Jesus doesn’t do away with the idea of priests and sacrifice. Rather he perfects the old law and shows us a deeper meaning. Jesus is sinless and has no need to offer sacrifice first for his own sins and then for others. He is the perfect priest. Then, in an amazing development, the sacrifice he offers is also perfect because he offers himself. No longer are imperfect lambs offered over and over, but the perfect Lamb of God becomes the perfect sacrifice that once and for all takes away the sins of the world.

This is what we are doing when we come to Mass. This is how our sins today are taken away by the one sacrifice of the Lamb of God 2000 years ago. This is why the Mass has traditionally and rightly been called, “The Holy Sacrifice of the Mass.”