Roman Catholics are quick to say that the Eucharist is not a re-sacrifice of Christ. They want to make it clear that Christ was offered once for all and that the Mass is not a re-sacrifice but a "re-presentation" of the sacrifice. We certainly do not want to misrepresent Roman Catholic theology, but we must ask how it is possible for the Mass to not be a re-sacrifice of Christ when the Mass is called a divine sacrifice (CCC, 1068) that is done over and over again. We are told that "the sacrifice of Christ and the sacrifice of the Eucharist are one single sacrifice"; (CCC, 1367); that it is an unbloody offering that is proptiatory, (CCC, 1367); that it can make reparation of sins, (CCC, 1414); and is to be considered a true and proper sacrifice (The Catholic Encyclopedia, topic: "Sacrifice of the Mass"). We must conclude that it is a sacrifice that occurs over and over again and since it is said to be a true and proper sacrifice that is propitiatory, then logically it must be a re-sacrifice of Christ. If it is not, then how can it be called a sacrifice of Christ? Also, how could it be propitiatory if it is not a sacrifice of Christ since it is Christ's offering on the cross that is itself propitiatory?
That's a legitimate question, and the stakes are important. If the Eucharist is a re-Sacrifice of Christ, It's illegitimate, because Christ was slain "once for all" (Heb. 7:26-27). The answer is foreshadowed in the Passover. The Passover consists of three distinct parts:
- the slaying of the lamb (Exodus 12:5-6)
- the covering of the doorposts in blood (Exodus 12:7)
- the eating of the lamb (Exodus 12:8-10)
This foreshadowed Christ's Passion. The Slaying of the Lamb of God occurred once for all time at the Crucifixition. Covering ourselves in His Blood occurs most directly at Baptism, which is itself a one-time event. Yet the eating of the Lamb is something which we can do time and time again. Think about it: a Jew celebrating Passover could go for a second helping of the Lamb (and was in some cases required to, since it had to be eaten that day). But this second eating didn't mean a second sacrifice: they didn't have to re-kill or re-sacrifice (or even re-mark the doorposts) to consume the lamb. That's what it means when the Catechism says "the sacrifice of Christ and the sacrifice of the Eucharist are one single sacrifice." That's also why the Eucharist is termed the "unbloody Sacrifice," because the bloodshed was in the slaying of the Lamb, not the eating.
The Eucharist is therefore a vital part of the finished work of the Cross: specifically, it's the application of that work. This sounds, at first, foreign to most Protestants, but I don't think it is. Many Protestants can point to the day -even the hour- and the exact circumstances in which they got saved. But it was a point in their lifetime. Nobody says, "I got saved in c. 32 A.D., when Jesus died on the Cross." Certainly, it's because of that past one-time event that they're able to get saved, but they got saved when they were justified by faith through Grace, and that Blood was applied to them. His Blood was shed in c. 32, but it was applied to their doorposts (figuratively speaking) when they turned their life over to Christ.
So Protestants, like Catholics recognize a distinction between the shedding of Blood and the application of that shed Blood. This is also how non-Calvinists (and even some Calvinists) can reject the notion of limited atonement: the idea that Christ only died for certain folks. We say in response that His Blood is sufficient to cover everyone, and that "God so loved the world that he gave His only begotten Son, that whoever believes in Him shall not perish but have eternal life" (John 3:16). His Blood is shed out of Love for "the world," but only saves those it's applied to, that is, "whoever believes in Him."
Later today, I plan to post on the "Four Cups" of the Passover, an idea which Scott Hahn has explored in depth quite well, which also deals with the connection between the Passover, Last Supper, and Passion of Christ.