The Mass is the same sacrifice as the sacrifice of the cross, because in the Mass the Victim is the same, and the principal Priest is the same, Jesus Christ.
1. The Mass is the very same sacrifice which was offered up at the Last Supper and on Calvary; it is the living presence of the sacrifice of the Cross.
On Calvary, Christ offered Himself up by accepting a cruel death out of obedience to the heavenly Father and for our redemption. At the Last Supper, He offered Himself for the impending immolation: “This is my body. . . This is my blood of the new covenant, which is being (or will be) shed for many.” He added: “Do this in remembrance of me.” At Mass, the Victim immolated on Calvary is offered anew, by the priest repeating the same words with which Christ offered Himself at the Last Supper.
The Mass does not, strictly speaking, renew the sacrifice of the Cross. Christ has been immolated once for all. The Church, by the symbolic separation of body and blood (in the double consecration), represents the historic sacrifice and offers it anew to the heavenly Father. As St. Paul writes: “For as often as you shall eat this bread and drink this cup, you proclaim the death of the Lord, until he comes” (1 Corinthians 11:26).
2. The Mass is no mere remembrance or memorial of Calvary. Christ, the Victim of Calvary, is really present, and with Him the permanent power or efficacy of His great sacrifice. Through the new offering that power is now communicated and applied to the Church, to all of us. In this sense, the sacrifice of the Cross is present (sacramentally) in the Mass.
The priest offering the mass is Christ’s minister and representative. He utters the words of consecration in the name and person of Christ, saying: “This is My Body. This is My Blood;” not, “This is Christ’s Body, etc.”
The Mass is the chief and central act of Catholic worship, the greatest act of worship that can be offered to God, an infinite ocean of graces for the living and the dead.
The illustration shows the solemn blessing of the grapevines from which the grapes are taken to prepare wine for the consecration during the Sacrifice of the Mass.