Doctrine Concerning The Sacrifice Of The Mass from the Council of Trent
That the ancient, complete and in every way perfect faith and teaching regarding the great mystery of the Eucharist in the Catholic Church may be retained, and with the removal of errors and heresies may be preserved in its purity, the holy, ecumenical and general Council of Trent, lawfully assembled in the Holy Ghost, the same legates of the Apostolic See presiding, instructed by the light of the Holy Ghost, teaches, declares and orders to be preached to the faithful the following concerning it, since it is the true and only sacrifice.
THE INSTITUTION OF THE MOST HOLY SACRIFICE OF THE MASS
Since under the former Testament, according to the testimony of the Apostle Paul, there was no perfection because of the weakness of the Levitical priesthood, there was need, God the Father of mercies so ordaining, that another priest should rise according to the order of Melchisedech, our Lord Jesus Christ, who might perfect and lead to perfection as many as were to be sanctified. He, therefore, our God and Lord, though He was by His death about to offer Himself once upon the altar of the cross to God the Father that He might there accomplish an eternal redemption, nevertheless, that His priesthood might not come to an end with His death, at the last supper, on the night He was betrayed, that He might leave to His beloved spouse the Church a visible sacrifice, such as the nature of man requires, whereby that bloody sacrifice once to be accomplished on the cross might be represented, the memory thereof remain even to the end of the world, and its salutary effects applied to the remission of those sins which we daily commit, declaring Himself constituted a priest forever according to the order of Melchisedech, offered up to God the Father His own body and blood under the form of bread and wine, and under the forms of those same things gave to the Apostles, whom He then made priests of the New Testament, that they might partake, commanding them and their successors in the priesthood by these words to do likewise: Do this in commemoration of me, as the Catholic Church has always understood and taught. For having celebrated the ancient Passover which the multitude of the children of Israel sacrificed in memory of their departure from Egypt, He instituted a new Passover, namely, Himself, to be immolated under visible signs by the Church through the priests in memory of His own passage from this world to the Father, when by the shedding of His blood He redeemed and delivered us from the power of darkness and translated us into his kingdom. And this is indeed that clean oblation which cannot be defiled by any unworthiness or malice on the part of those who offer it; which the Lord foretold by Malachias was to be great among the Gentiles, and which the Apostle Paul has clearly indicated when he says, that they who are defiled by partaking of the table of devils cannot be partakers of the table of the Lord, understanding by table in each case the altar. It is, finally, that [sacrifice] which was prefigured by various types of sacrifices during the period of nature and of the law, which, namely, comprises all the good things signified by them, as being the consummation and perfection of them all.
THE SACRIFICE OF THE MASS IS PROPITIATORY BOTH FOR THE LIVING AND THE DEAD
And inasmuch as in this divine sacrifice which is celebrated in the mass is contained and immolated in an unbloody manner the same Christ who once offered Himself in a bloody manner on the altar of the cross, the holy council teaches that this is truly propitiatory and has this effect, that if we, contrite and penitent, with sincere heart and upright faith, with fear and reverence, draw nigh to God, For, appeased by this sacrifice, the Lord grants the grace and gift of penitence and pardons even the gravest crimes and sins. For the victim is one and the same, the same now offering by the ministry of priests who then offered Himself on the cross, the manner alone of offering being different. The fruits of that bloody sacrifice, it is well understood, are received most abundantly through this unbloody one, so far is the latter from derogating in any way from the former. Wherefore, according to the tradition of the Apostles, it is rightly offered not only for the sins, punishments, satisfactions and other necessities of the faithful who are living, but also for those departed in Christ but not yet fully purified.
Taken from the Council of Trent Session XXII - The sixth under the Supreme Pontiff, Pius IV, celebrated on the seventeenth day of September, 1562
