[Jesus Christ], 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,[2] 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,[3] 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,[4] as the Catholic Church has always understood and taught.