For as often as you eat this bread and drink the cup, you proclaim the death of the Lord until he comes.  [1Cor 11:26]
One aspect of the reality of the Eucharist is the reality of the sacrifice, the offering, the oblation, new and eternal covenant in Jesus whom God set forth as an expiation, through faith, by his blood, [Rom 3:25] blood which He gave in obedience to His Father in reparation for my sins. I couldn’t do it; I am a sinner. God couldn’t do it; He is the sinned against. The God-Man, Jesus, needed to do it, taking upon himself our sins and becoming our divine/human oblation expressing our sorrow for sin, and God’s acceptance of our sacrifice, our “making holy” of ourselves.
It is very clear that, instead of holocausts and sin offerings, Jesus offers the Father what He wants, what He wanted from the beginning, from Eden: Behold, I come to do your will. His perfect obedience, even to drinking the cup of death, is the one sacrifice for sins; it not only counterbalances but completely obliterates sin which, at its root, each and every one of which stems from disobedience to God. [Heb 10:8-9,12]
In order to take part in His sacrifice, His “making holy,” I need to join Him in some way; it is my sin, it therefore must be a sacrifice on my part. But even if I give away everything I own, and if I hand my body over to be martyred, I gain nothing [1Cor 13:3] if I am not connected, not part of Christ, not part of Love incarnate, for God is love. In this way the love of God was revealed to us: God sent his only Son into the world so that we might have life through him.[1Jn 4:8-9] That word life rings a bell… Unless you eat the flesh of the Son of Man and drink his blood, you do not have life within you. Just as the living Father sent me and I have life because of the Father, so also the one who feeds on me will have life because of me. [Jn 6:53, 57]
But that’s not the end of the story: In this is love: not that we have loved God, but that he loved us and sent his Son as expiation for our sins.[1Jn 4:10] Through the blood of Jesus we have confidence of entrance into the sanctuary by the new and living way he opened for us through the veil, that is, his flesh [Heb 19-20]. I must become part of His sacrifice, partake in His real flesh and blood, which He offered to the Father once for all on the Cross and which is perpetuated forever in the sharing of Himself at the holy sacrifice of the Mass.
Without His real presence, His body and blood which we partake, all this remembering becomes just a mime, a play, a pious but literally unsubstantial, i.e. without the substance of Jesus present, reenactment of a script instead of what truly happened, what truly happens and truly will happen until the end of time, Jesus eternal sacrifice to the Father in which He invites us to join, He blesses, breaks and gives to me to eat, gives to me to drink.
Neither the author of Hebrews, Paul, or the Church would put such emphasis into our attitude, our reverence, our self-cleansing for an unsubstantial reenactment: Let us approach with a sincere heart and in absolute trust, with our hearts sprinkled clean from an evil conscience and our bodies washed in pure water. [Heb 10:22] Nor would there be such emphasis on participation: We should not stay away from our assembly, as is the custom of some, but encourage one another, and this all the more as you see the day drawing near. [Heb 10:25]
Nor would participating in a memory unworthily be cause for condemnation. But if I receive the true body, the true blood and then sin deliberately after receiving knowledge of the truth, my joining with Christ no longer remains a sacrifice for sins but a fearful prospect of judgment and a flaming fire that is going to consume the adversaries. As Hebrews points out by comparison: Anyone who rejects the law of Moses is put to death without pity on the testimony of two or three witnesses. Do you not think that a much worse punishment is due the one who has contempt for the Son of God, considers unclean the covenant-blood by which he was consecrated, and insults the spirit of grace?[Heb 10:26-29] Therefore whoever eats the bread or drinks the cup of the Lord unworthily will have to answer for the body and blood of the Lord. For anyone who eats and drinks without discerning the body, eats and drinks judgment on himself.[1Cor 11:27,29]…Without discerning the body, without believing that Jesus is really present, that this bread is His Body, this wine His blood…You have to believe or answer for your unbelief. A person should examine himself, and so eat the bread and drink the cup.[1Cor 11:28] It is a fearful thing to fall into the hands of the living God. [Heb 10:31]
I do not pretend to understand the total picture. I do know that in order for this sacrifice to be real, here, today, He has enabled us, through the priesthood handed down from the Apostles, to do this in His memory, to call again on the Spirit, to enact His Sacrifice and to invite me to join Him in offering to the Father myself, to transubstantiate again bread and wine into His body and blood and offer them again on our altar in West Pawlet, in Moscow, in Johannesburg, in Beijing, yesterday, today, tomorrow until the end of time.
 Scripture texts in this work are taken from the New American Bible, revised edition © 2010, 1991, 1986, 1970 Confraternity of Christian Doctrine, Washington, D.C. and are used by permission of the copyright owner. All Rights Reserved. No part of the New American Bible may be reproduced in any form without permission in writing from the copyright owner.