The Eucharist.

This is an extremely important topic for Catholics in discussions with non-Catholics. Almost all Protestants have a reverence for the “Lord’s Supper,” and some denominations, such as Lutherans and members of the Episcopal Church, have a sacramental attitude toward the Eucharist that approaches the teaching of the Catholic Church (i.e., that at the moment of transubstantiation, Christ is sacra mentally, truly, and substantially present in body and blood, soul and divinity under the species of bread and wine). Also assuming almost universal agreement among Protestants on this doctrine, Catholics must be prepared to use Scripture to explain why the Church proclaims the dogma of transubstantiation and the Real Presence of Christ in the Eucharist.
First, as the next few passages will show, the Passover event in the Old Testament most dramatically prefigures the Eucharistic sacrifice and its relationship to Christ’s saving sacrifice on the cross – our eternal Sacrifice and eternal High Priest. At the Last Supper, Christ fulfilled the Old Testament disfigurement of the Passover by his institution of the Eucharist. Just as the “lamb” was ritually sacrificed in the Old Testament and with his blood have anointed the porches of the houses of the faithful Jews who, under Moses’ leadership, awaited their release from the captivity and slavery they had endured in Egypt, so likewise is Christ the “Lamb of God” whose death on the cross “takes away the sins of the world.” Our worthy reception of the Eucharist and participation in the sacrifice of the Holy Mass makes us truly present at the cross and in the heavenly temple where Christ, the supreme High Priest, offers His perfect sacrifice to the Father on our behalf.
Verse Jn 1:28-30 should be linked with Ex 12:8 and 12:46, where Moses is told that the flesh of the sacrificial Passover lamb (a type of Jesus Christ, the Lamb of God) must be eaten on the night of the first Passover. This Old Testament image of the slain lamb being eaten by God’s people (who were protected from the angel of death by the blood of the lamb, which they sprinkled on the faithful home), is a disfigurement of the Blessed Sacrament. Christ, the Lamb of God, who
takes away the sins of the world, protects us from eternal death by his blood, which was shed for us on the cross. (Ed. note: St. John Chrysostom: “Now, therefore, the enemy will withdraw much sooner, when will see no longer the blood of the image on the door, but the true blood shining on the mouths of the faithful, for it sanctifies the faithful of the temple of Christ.”)
Compare the meaning of the Passover with the Mass, the sacrifice of the lamb with the sacrifice of Christ, and the people, whom God commanded to eat the lamb, with the people, whom God commanded to eat the body and blood of Christ in the Eucharist: “Unless you eat the flesh of the Son of Man and drink his blood, you will not have life in yourselves” (Jn 6:53). Paul speaks of this connection in /Cor 5:7 when he calls Christ “our Passover lamb” who was “sacrificed” for us.
* Ex 12:1-13: “The Lord said to Moses and Aaron in Egypt, ‘This month will be a beginning month for you, the first month of the year.
In the tenth On the tenth day of this month, let every man provide a lamb for his family, a lamb for every house. If the family is smaller and could not eat a lamb, let it join with the neighbor who lives nearest to his house, according to the number of persons, how many are enough for to eat the lamb? The lamb must be without blemish, a male lamb of one year old; you may pick him out of the sheep or kids. You shall keep it until the fourteenth day of this month; on the eve of the month, the whole congregation of Israel shall sacrifice it. They shall take off his blood and anoint with it both the porch and the lintel of the door of the houses in which they shall eat it. And on that night
they shall eat flesh roasted with fire and unleavened bread with bitter herbs. None of it shall be eaten raw or boiled in water, that is, only on
baked with fire. You shall also eat the head, the feet, and the entrails. Nothing of it shall be left until morning; if there is anything left of it, you shall burn it on the fire. And you shall eat it like this: Your loins shall be girded, your sandals with sandals on your feet, and staff in your hand. You shall eat quickly, for it is the Lord’s Passover. On that night I will pass through the land of Egypt and will kill all the firstborn in Egypt; man, beginning from even to the cattle. And over all the gods of Egypt. I will execute judgment. I am the Lord! The blood on your houses shall be a sign that you dwell in them. I will see
blood, and I will pass over them; no plague shall befall you when I smite Egypt.'” Ex 12:21-28: “Moses called all the elders of the children of Israel and said to them: “Go, take. “And you shall dip a bundle into the blood in a basin of hyssop and anoint with it the lintel of the door and both porches of your house, for the Lord will pass by and smite the Egyptians. But when he sees the blood on the upper and both the lintels, he will pass by the door, and will not suffer the corrupter to come into your houses and destroy. Keep this commandment as a statute for yourselves and your sons forever. Also, when ye come into the land which the Lord shall give you, as..you shall keep these ordinances. And when your sons ask you, “What does this ceremony mean?” you shall say to them: “It is the sacrifice of the paschal lamb to the Lord as when he passed by the houses of the children of Israel in Egypt, when he smote when he smote the Egyptians, and when he spared our houses.’