All nations—whether Jews, idolaters or Christians, except Mahometans and modern Protestants—have made sacrifice their principal act of worship. If you go back to the very dawn of creation, you will find the children of Adam offering sacrifices to God. Abel offered to the Lord the firstlings of his flock, and Cain offered of the fruits of the earth.
The sacrifice of the Mass is the consecration of the bread and wine into the body and blood of Christ, and the oblation of this body and blood to God, by the ministry of the Priest, for a perpetual memorial of Christ’s sacrifice on the cross. The Sacrifice of the Mass is identical with that of the cross, both having the same victim and High Priest—Jesus Christ.