Saint Paul’s doctrine of the believer’s participation in Christ finds its high point in the Apostle’s doctrine of the Eucharist, which he called “the Supper of the Lord” (1 Cor 11:20) or “the Breaking of the Bread” (Acts 20:7). Some time before a.d. 100, the ritual of the Lord’s Supper came to be known as the Eucharist. We find the term Eucharist being applied to the Lord’s Supper in the early late first-century Christian document, the Didache: “Now as regards the Eucharist, give thanks after this manner…” There are two reasons for why the Lord’s Supper came to be known as the Eucharist. The first is that the Greek word eucharistia means “giving thanks.” The earliest use of eucharistia in the context of the Lord’s Supper is from the writings of Saint Paul. Paul uses a Greek form of the word eucharistia in 1 Cor 11:24 when he describes how the Lord’s Supper was celebrated:
And when he had given thanks (Greek: eucharistésas or “eucharisted”), he broke it, and said, “This is my body which is for you. Do this in remembrance of me” (1 Cor 11:24).
Saint Paul’s First Epistle to the Corinthians was written in about a.d. 57 and so the Apostle’s account of the Eucharist is the earliest testimony to the ritual and beliefs surrounding the Lord’s Supper. The accounts of the Lord’s Supper found in the Matthew, Mark, and Luke were composed sometime after a.d. 57 and so Paul’s description in the eleventh chapter of First Corinthians is the oldest. Less than one hundred years after the death of Saint Paul, we find Saint Justin Martyr writing to the pagan Emperor Antonius Pius (a.d. 138-161) in order to explain the way in which Christians at this time celebrated the Eucharist:
On the day we call the day of the sun [i.e. Sunday], all who dwell in the city or country gather in the same place.
The memoirs of the apostles and the writings of the prophets are read, as much as time permits. When the reader has finished, he who presides over those gathered admonishes and challenges them to imitate these beautiful things.
Then we all rise together and offer prayers for ourselves…and for all others, wherever they may be, so that we may be found righteous by our life and actions, and faithful to the commandments, so as to obtain eternal salvation. When the prayers are concluded we exchange the kiss.
Then someone brings bread and a cup of water and wine mixed together to him who presides over the brethren. He takes them and offers praise and glory to the Father of the universe, through the name of the Son and of the Holy Spirit and for a considerable time he gives thanks (he “eucharists”) that we have been judged worthy of these gifts. When he has concluded the prayers and thanksgivings, all present give voice to an acclamation by saying: “Amen!”
When he who presides has given thanks and the people have responded, those whom we call deacons give to those present the eucharisted bread, wine and water and take them to those who are absent.
Here we find not only the use of Paul’s word eucharistia, but also the structure that he laid down in the Church at Corinth. Let us now turn to those passages in the tenth and eleventh chapters of 1 Corinthians in which Saint Paul explains the meaning of the Eucharist.
The second reason why the Lord’s Supper came to be known as the Eucharist is that the Greek word eucharistia meaning “thanksgiving” corresponded perfectly to the Old Testament sacrifice known as the todah offering. In Hebrew, the word todah also means “thanksgiving.” Accordingly, the New Testament authors use the word eucharistia as a Greek translation of the Hebrew todah meaning “thanksgiving sacrifice.”
In the Old Testament, we read that the todah thanksgiving sacrifices were offered with wheat flour and wine (Num 15:1-10). This sacrifice of wheat and wine evokes the sacrifice of bread and wine offered by Melchizedek who blessed the patriarch Abraham (Gen 14:18). We learn that Christ is a “priest according to the order of Melchizedek” (Heb 7:1-17), and so Jews would expect the Messiah to offer a sacrifice of bread and wine. Moreoever, read that King David offered the todah sacrifice with bread and wine (1 Chr 16:3). We also read about how the prophet Jonah, having been swallowed by the whale, vowed to the Lord a todah sacrifice if he should be delivered from death after spending three days in darkness (Jon 2:3-10). The earliest Christians came to perceive that the Last Supper of Christ was in fact a todah sacrifice of bread and wine in union with the sacrifice of Christ. The Davidic todah—thanksgiving theme and the promised todah—thanksgiving of Jonah who also rose from the belly of the fish on the third day confirmed that the wheat and wine ritual of Christ hearkened back to the bread and wine “thanksgiving” offering of the Old Testament.
In the Old Covenant, bread and wine were offered in sacrifice among the first fruits of the earth as a sign of grateful acknowledgment to the Creator. But they also received a new significance in the context of the Exodus: the unleavened bread that Israel eats every year at Passover commemorates the haste of the departure that liberated them from Egypt; the remembrance of the manna in the desert will always recall to Israel that it lives by the bread of the Word of God; their daily bread is the fruit of the promised land, the pledge of God’s faithfulness to his promises.
The “cup of blessing” at the end of the Jewish Passover meal adds to the festive joy of wine an eschatological dimension: the messianic expectation of the rebuilding of Jerusalem. When Jesus instituted the Eucharist, he gave a new and definitive meaning to the blessing of the bread and the cup (CCC §1334).
Consequently, the Catholic Church teaches that the Eucharist is not merely a meal, but that it is also the one true sacrifice of Christ, re-presented throughout the ages. Martin Luther and subsequent Protestant leaders rejected the sacrificial aspect of the Eucharist. Citing Hebrews 10:10, the Protestants held that Christ died “once for all.” They could not perceive how every single Eucharistic celebration could also be that same sacrifice of Christ offered “once for all.” It seemed to them that the Catholic Church taught that Christ was repeatedly slain and sacrificed over and over upon every altar of the Catholic Church. If this were true, it would have indeed been a grave error. However, the Catholic Church, in agreement with the Epistle to the Hebrews, does not teach that Christ dies repeatedly on the altar. Rather, the Church agrees that Christ died “once for all”—once for all time. Christ died once but the application of this sacrifice is for all time and for all people. Christ does not die again but the single offering of His Body and Blood on the cross is re-presented in the Eucharistic sacrifice and applied to those who receive Holy Communion. In other words, the sacrifice on Calvary and the sacrifice on the altar are one and the same, their mode being different.
The Catholic Council of Trent (1545-1563) in the wake of the Protestant Reformation explained the mystery of Christ’s one sacrifice and the sacrifice of the Eucharist in detail:
He, therefore, our God and Lord, though He was about to offer Himself once on the altar of the cross unto God the Father, by means of his death, there to operate an eternal redemption; nevertheless, because that His priesthood was not to be extinguished by His death, in the last supper, on the night in which He was betrayed—that He might leave, to His own 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, and the memory thereof remain even unto the end of the world, and its salutary virtue be applied to the remission of those sins which we daily commit.
The Council of Trent next cites the Apostle Paul as evidence for the doctrine of Eucharistic sacrifice:
The Apostle Paul, writing to the Corinthians, has not obscurely indicated, when he says, that they who are defiled by the participation of the table of devils, cannot be partakers of the table of the Lord; by the table, meaning in both places the altar.
The Council of Trent is, of course, referring to the passage in First Corinthians where Paul compares the sacrifice of the Christian Eucharist to the sacrifices of Israel and the sacrifices of pagans:
The cup of blessing which we bless, is it not a participation in the blood of Christ? The bread which we break, is it not a participation in the body of Christ? Because there is one bread, we who are many are one body, for we all partake of the one bread.
Consider the people of Israel. Are not those who eat the sacrifices partners in the altar? What do I imply then? That food offered to idols is anything, or that an idol is anything? No, I imply that what pagans sacrifice they offer to demons and not to God. I do not want you to be partners with demons. You cannot drink the cup of the Lord and the cup of demons. You cannot partake of the table of the Lord and the table of demons (1 Cor 10:18-21).
Here again we find a striking example of Paul’s doctrine of participation. First, Christians participate in the Body and Blood of Jesus Christ through the Eucharistic meal. Second, the people of Israel who ate the Old Testament sacrifices were “partners in the altar.” Third, pagans who sacrifice meat to idols, that is to say demons, become “partners with demons.” Last of all, Paul concludes that a Christian “cannot partake of the table of the Lord and the table of demons.” Just as Israelite sacrifices and pagan sacrifices allowed worshippers to partake of spiritual realities through their altars, so also Christians become partakers of the sacrifice of Christ through the Eucharist.
It is indeed odd that Protestants deny that the “Lord’s table” is an “altar” since Paul so clearly identifies the “table of the Lord” with an “altar” in this passage. This antagonism to “Christian altars” is especially unwarranted when we consider that the Epistle to the Hebrews explicitly states that the Church of Jesus Christ worships at an altar from which we eat and drink the sacrifice of Christ:
We have an altar from which those who serve the tent [i.e. the Old Testament tabernacle] have no right to eat. For the bodies of those animals whose blood is brought into the sanctuary by the high priest as a sacrifice for sin are burned outside the camp. So Jesus also suffered outside the gate in order to sanctify the people through his own blood (Heb 13:10-13).
This passage in Hebrews indicates that Christians possess an altar that corresponds to the altar of Jewish tabernacle in Jerusalem. Whereas the Jewish people sacrificed the body and blood of bulls and goats on that altar, Christians have an altar from which even the Jewish priests “have no right to eat.” The sacrifice which the Christians eat is “Jesus who suffered” and who sanctified “the people through his own blood.”
The passage no doubt refers to the Christian Eucharist of which Christians have a right to eat as partakers of Christ. If we peal back the English translation of Hebrews 13:10-13 we see that the Greek word for altar is thusiasterion. This word is a compound of the Greek word thusia (“sacrifice”) and sterion (“fixed place”). To render it literally, Hebrews 13:10 reads: “We have a fixed place of sacrifice.” The concept of Eucharistic sacrifice is built in to the very word for altar as a place of sacrifice.
 Didache 9:1.
 Saint Justin Martyr, First Apology 1, 65-67 (Patrologia Graeca 6, 428-429).
 Council of Trent, Session 22, Chapter 1.
 Council of Trent, Session 22, Chapter 1.