The Jews quarreled among themselves, saying, "How can this man give us (his) flesh to eat?" Jesus 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. Whoever eats my flesh and drinks my blood has eternal life, and I will raise him on the last day. For my flesh is true food, and my blood is true drink. Whoever eats my flesh and drinks my blood remains in me and I in him. 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. This is the bread that came down from heaven. Unlike your ancestors who ate and still died, whoever eats this bread will live forever." These things he said while teaching in the synagogue in Capernaum. (Jn 6:52-59)
It is interesting that Jesus, a Jew, is talking about drinking blood. Jews would not drink the blood and drinking blood was absolutely forbidden (Lev 17: 10-14). Even the flesh of the animal that is eaten should be drained of all blood. Blood was offered only to God and God drank the blood. Jews believed that blood contained life in it and only God drank blood.
“Eat my flesh” and “drink my blood” could mean a lot of things in the biblical context. One is that it has a reference to the last supper of Jesus. Another could be the sacramental food and drink in the Eucharist. Jesus also means that eating his flesh and drinking his blood could also mean being united with him.
Those who eat of his body and drink of his blood are they that form the people of the new exodus. In the old exodus the ancestors of the Jews ate and drank in the wilderness but they died. But the difference with the new Israel is that they will never die and they will possess eternal life. So union with Jesus or the sacramental relationship with Jesus or the communion with him in his last supper will reward the individual with eternal life.
