This oblation of the New Law is commonly called _Mass_. The word Mass is derived by some from the Hebrew term _Missach_ (Deut. xvi.), which means a free offering. Others derive it from the word _Missa_, which the Priest uses when he announces to the congregation that Divine Service is over. It is an expression indelibly marked on our English tongue from the origin of our language, and we find it embodied in such words as _Candlemas_, _Michaelmas_, _Martin-mas_ and _Christmas_.
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.
The only difference consists in the manner of the oblation. Christ was offered up on the cross in a bloody manner, and in the Mass He is offered up in an unbloody manner. On the cross He purchased our ransom, and in the Eucharistic Sacrifice the price of that ransom is applied to our souls. Hence, all the efficacy of the Mass is derived from the sacrifice of Calvary.
It was on the night before He suffered that our Lord Jesus Christ instituted the Sacrifice of the New Law. "Jesus," says St. Paul, "the night in which He was betrayed took bread, and, giving thanks, broke and said: Take ye and eat; this is My body which shall be delivered for you. This do for the commemoration of Me. In like manner also the chalice, after He had supped, saying: This chalice is the new testament in My blood. This do ye, as often as you shall drink, for the commemoration of Me; for as often as ye shall eat this bread, and drink the chalice, ye shall show the death of the Lord until He come."(397)
From these words we learn that the principal motive which our Savior had in view in instituting the Sacrifice of the Altar was to keep us in perpetual remembrance of His sufferings and death. He wished that the scene of Calvary should ever appear in panoramic view before our eyes, and that our heart, memory and intellect should be filled with the thoughts of His Passion. He knew well that this would be the best means of winning our love and exciting sorrow for sin in our soul; therefore, He designed that in every church throughout the world an altar should be erected, to serve as a monument of His mercies to His people, as the children of Israel erected a monument, on crossing the Jordan, to commemorate His mercies to His chosen people. The Mass is truly the memorial service of Christ's Passion.