Chapter XXIII. The Sacrifice Of The Mass. 297 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. In compliance with the command of our Lord the adorable Sacrifice of the Altar has been daily renewed in the Church, from the death of our Savior till the present time, and will be [313] perpetuated till time shall be no more. In the Acts it is said that while Saul and others were ministering (or, as the Greek text expresses it, sacrificing) to the Lord, and fasting, the Holy Spirit said to them: "Set apart for Me Saul and Barnabas." St. Paul, in his Epistle to the Hebrews, frequently alludes to the Sacrifice of the Mass. "We have an altar," he says, ""whereof they cannot eat who serve the tabernacle."398 The Apostle here plainly declares that the Christian church has its altars as well as the Jewish synagogue. An altar necessarily supposes a sacrifice, without which it has no meaning. The Apostle also observes that the priesthood of the New Law was substituted for that of the Old Law.399 Now, the principal office of Priests has always been to offer sacrifice. Priest and sacrifice are as closely identified as judge and court. St. Paul, after David, calls Jesus "a Priest forever, according to the order of Melchisedech."400 He is named a Priest because He offers sacrifice; a Priest forever because His sacrifice is perpetual; according to the order of Melchisedech because He offers up consecrated bread and wine, which were prefigured by the bread and wine offered by "Melchisedech, the Priest of the 400 Ps. cix. 4; Heb. v. 6.