.

The Israelites, who worshipped the true God and offered Him sacrifices
because He made known to them by revelation that they should do so, had
four kinds of sacrifice. They offered one for sin, another in
thanksgiving for benefits received, another as an act of worship, and
another to beg God's blessing. It is just for these four ends or objects
we offer up the one Christian sacrifice of the holy Mass. In the
beginning the head of the family offered sacrifice--as Noe did when he
came out of the Ark--but after God gave His laws to Moses He appointed
priests to offer up the sacrifices. Aaron, the brother of Moses, was the
first priest appointed, and after him his descendants were priests. When
Our Lord came and instituted a new sacrifice He established the
priesthood of the New Law, and appointed His own priests, namely, the
Apostles, with St. Peter as their chief, and after them their lawfully
appointed successors, the bishops of the world, with the Pope as their
chief. The sacrifices of the Old Law were figures of the sacrifice of
the New Law, and were to cease at its institution; and when the ancient
sacrifices ceased the ancient priesthood was at an end.

265 Q. Is the Mass the same sacrifice as that of the Cross?
A. The Mass is the same sacrifice as that of the Cross.

But how is the Mass a sacrifice? It is a sacrifice because at the Mass
the body and blood of Our Lord are offered to His heavenly Father at the
consecration, and afterwards consumed by the priest. In offering up the
body and blood of Our Lord the bread and wine are consecrated
separately, and kept separate on the altar at Mass to signify their
separation at Our Lord's death in the sacrifice of the Cross, when His
sacred blood flowed from His body. The Holy Eucharist is also a
Sacrament, because it has the three things necessary to constitute a
Sacrament; namely, (1) The outward sign--that is, the appearance of
bread and wine. (2) The inward grace; for it is Jesus Christ Himself,
the Author and Dispenser of all graces. (3) It was instituted by Our
Lord.

The Holy Eucharist is therefore both a sacrifice and a Sacrament. It is
a sacrifice when offered at Mass, and a Sacrament when we receive it and
when it is reserved in the tabernacle.

*266 Q. How is the Mass the same sacrifice as that of the Cross?
A. The Mass is the same sacrifice as that of the Cross because the
offering and the priest are the same--Christ Our Blessed Lord; and the
ends for