Jn 6:52-59
52The Jews quarreled among themselves, saying, “How can this man give us [his] flesh to eat?” 53Jesus said to them, “Amen, amen, I say to you, unless you eat the flesh of the Son of Man and drink his blood, you do not have life within you. 54Whoever eats my flesh and drinks my blood has eternal life, and I will raise him on the last day. 55For my flesh is true food, and my blood is true drink. 56Whoever eats my flesh and drinks my blood remains in me and I in him. 57Just 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. 58This is the bread that came down from heaven. Unlike your ancestors who ate and still died, whoever eats this bread will live forever.” 59These things he said while teaching in the synagogue in Capernaum.
FLESH AND BLOOD: “Flesh and blood” is a phrase that can be understood from two different perspectives.Relative to human beings, “flesh and blood” means man as a created, therefore, mortal, perishable entity. It is often used to contrast human beings with God and other “sky beings” (angels, spirits). When St. Paul says that he did not consult “flesh and blood” when he preached the Gospel after his conversion, he means that he received his commission from God directly, not from men, not even the apostles.
Relative to animals, “flesh and blood” is used to make proper distinction concerning what human beings may eat. Blood is always prohibited because blood is the life of the creature and it belongs to God. “Only, you shall not eat flesh with its life, that is, its blood.” In the temple sacrifice, the blood is poured against the altar which represents God.
“Flesh” may directly refer to “fat” which, in Israel’s tradition, is considered the “seat of life” together with blood. “All the fat belongs to the Lord” (Lv 3:16). In the temple sacrifice, the fat is burned to go up in smoke to the Lord.
Thus the prohibitions single out animal parts that serve as the seat of life—because life is from God alone and belongs to God alone.
In the “anti-language” of John’s Gospel, Jesus says that his flesh and blood are the source of eternal life (Jn 6:54). Ironically, it is by eating what is “prohibited” as food to human beings that they are able to receive true life. During the Last Supper, Jesus turns the bread and wine into his body and blood and commands his followers to “take, eat, and drink.” To ingest Jesus’ flesh and blood is to believe, accept, and welcome him who offered his “body and blood” in the sacrifice of Calvary, and to offer the sacrifice in an un-bloody way in the Eucharist.