The Mass is the central liturgical service of the Eucharist in the Catholic Church, in which bread and wine are consecrated and become the body and blood of Christ.

In Catholic teaching, the holy sacrifice of the Mass is the fulfillment of all the sacrifices of the Old Covenant. In the New Covenant, the one sacrifice on the altar of Calvary is revisited during every Catholic Mass. Jesus Christ merited all graces and blessings for us by His death on the Cross. These merits form an inexhaustible fountain of grace to nourish the supernatural life of souls.