Truly that passage, by itself, sounds unassailable. Christians are Spirit-filled people who need only the dove and the cross as the symbols of the world’s salvation. It’s all found in the Bible plain and clean. How messy and complicated Catholicism seems with its’ sacraments and crucifixes and hierarchy!
But the fact is, there is a context in which Jn. 6:63 resides. We know that whenever Jesus says, “I tell you most solemnly,” He is about to say something He considers to be of great import. In Jn. 6:53 He says, “I tell you most solemnly, if you do not eat the flesh of the Son of Man and drink his blood, you will have no life in you. Anyone who does eat my flesh and drink my blood has eternal life, and I shall raise him up on the last day. For my flesh is real food, and my blood is real drink. He who eats my flesh and drinks my blood lives in me and I live in him.” Actually, the word used here for eating is more like gnawing—gnawing on His flesh. The more His audience objects, the more emphatic Jesus becomes. Even when many of His disciples leave Him, He does not call them back to explain that he was only speaking figuratively.
It really seems unlikely that Jesus would go to such lengths to stress the necessity of actually consuming His flesh and blood, and then after alienating so many followers, deny it all. So what is the point of His words regarding the spirit giving life and the flesh being of no avail?
The key, I believe, lies in the point of His Incarnation. He could have redeemed us in merely a spiritual way—without the shedding of blood and all the mess. Instead He chose to become flesh and live a human life. Further, He chose to show His love for us by sacrificing Himself as the perfect sacrificial Lamb—which harkens back to the lamb of Passover—which was consumed by the community. Each context rests on the one preceding it.
By His agony on the cross Jesus, tells us more about who God is than anywhere else. And we understand because we are flesh and we know what physical suffering is. It is through the suffering and death of His body that we receive His life. “By His wounds we are healed” (Isaiah 53:5). So Jesus was not saying that flesh is of no value. Apart from the Spirit, it has no value. He used His flesh in the service of the Spirit. So consuming it is not an act of cannibalism, but an act of grace. When we use our flesh in the service of the Spirit, we grow spiritually. In such an instance, the body becomes a vehicle of grace. Besides, since Jesus is the Second Person of the Holy Trinity, His flesh has to be of supreme value by that very fact.
Certainly His suffering and death do not exhaust His love for us. His love is infinite; having no limit. So He shows us His infinite love in a human way that we can grasp. But that almighty God would join us in our humanity and allow Himself to be tortured and put to death by the creatures of His own making for their benefit—is more than we can wrap our finite minds around.
That eternal moment in which He died transcends all time and covers everyone who has ever lived or will live. And yet it remains in time as the Eucharist: the mystical presence that can inhabit our very flesh as well as our spirits. This is truly the holiest of Communions!
So what is the point of the Eucharist?
As St, Thomas Aquinas wrote: "As He was on the point of leaving His disciples, he left it as a perpetual memorial of His Passion. It was the fulfillment of ancient figures (e.g., the manna, the Paschal lamb) and the greatest of all His miracles, while for those who were to experience the sorrow of His departure, it was destined to be a unique and abiding consolation."