Flesh and blood are used with double meaning in the bread of life discourse. The Jews (John’s favorite way of providing opponents for dialogue with Jesus) understand flesh to be human flesh. To eat Jesus’ flesh, then, is to engage in cannibalism. Likewise, to drink blood is not only cannibalistic, but it is to defile life itself. The culture of the time believed that life was found in blood. Therefore, blood was sacred.
The verb for feeding is also used in two ways. It means to munch or to gnaw, as an animal eats the prey it has caught. However, it can also refer to human eating in terms of providing nourishment for one’s body.
John is drawing a parallel between eating flesh and eating the bread of life and drinking blood and drinking the wine of eternal life. When the members of the Johannine community gathered to break bread and to share the cup in memory of Jesus, the author wanted them to be aware that the food they ate and the wine they drank were real nourishment for eternal life.
The meaning of “flesh,” “blood,” and “feed” that one chooses depends on faith. Faith is the window through which one looks; it determines what one sees. The man or woman of faith sees bread and wine, which are the flesh and blood of Jesus. The person who does not believe sees only bread and wine.
By eating the flesh and blood of Jesus, a believer remains united to God’s life (cf v 57). Jesus is the food and drink that provides eternal life, just as bread and wine provide nourishment for earthly life.
People of the past ate the “bread that came down from heaven”—the manna—but they died. By eating the flesh and blood of Jesus, people can now live forever.