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 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. At Calvary, Christ not only merited all graces for people but also established certain channels whereby these graces