Jesus uses an impossible metaphor not unlike the earlier use of being “born again” to underscore the tension between the commitment demanded by living in the new community gathered around Jesus and loyalty to a prior social reality.
“I am the living bread that came down from heaven. Whoever eats of this bread will live forever; and the bread that I will give for the life of the world is my flesh.” The crowd then disputed among themselves, saying, “How can this man give us his flesh to eat?” So Jesus said to them, “Very truly, I tell you, unless you eat the flesh of the Son of Man and drink his blood, you have no life in you. Those who eat my flesh and drink my blood have eternal life, and I will raise them up on the last day; for my flesh is true food and my blood is true drink. Those who eat my flesh and drink my blood abide in me, and I in them. Just as the living Father sent me, and I live because of the Father, so whoever eats me will live because of me. This is the bread that came down from heaven, not like that which your ancestors ate, and they died. But the one who eats this bread will live forever.”