I remember my shock when I first heard this kind of question and observation coming from someone who was clearly a nonbeliever, an outsider:
Do you Christians really believe that you are eating Jesus' flesh and drinking his blood? That sounds like cannibalism.
Having grown up with a sense of the Real Presence at the heart of my faith, the language of eating flesh and drinking blood had never even hinted at cannibalism to me. But on hearing the question, I realized that, from the outsider's point of view, the question was an obvious one and deserved an answer. I came up with something like this: “We don't think of ourselves as consuming a dead body. The Eucharist is the way the risen Christ makes himself sacramentally available to us. Through this physical sign we encounter the risen Lord really present under the appearances of bread and wine.”
I still think that was a pretty good answer. But now, having studied John 6, especially the part that appears as this Sunday's Gospel, I realize that there is even more to the eating and drinking language in this passage. The context of the “eucharistic discourse” of John 6 entails an important Jewish tradition that still goes largely unnoticed in current teaching and preaching.
Anyone looking for the Eucharist in the Fourth Gospel soon discovers that there is no mention of Jesus' words linking the bread and cup with his Body and Blood in John's rendition of the Last Supper. In that scene the evangelist has chosen to focus entirely on Jesus' washing of the disciples’ feet. John has chosen another place to elaborate the meaning of eucharistic eating and drinking—the discourse in the Capernaum synagogue just after the feeding of the five thousand and the walking on the water. With the miracle of bread in the wilderness and Jesus’ own discourse about himself being greater than manna setting the stage, the primary background here is the biblical tradition of Moses leading people to the God-given manna in the desert.
This Sunday's First Reading from Deuteronomy 8 takes us to the origin of that tradition:
[God] therefore let you be afflicted with hunger, and then fed you with manna … in order to show you that not by bread alone does man live, but by every word that comes forth from the mouth of the Lord. (Deut 8:3)
How was God's word in the Torah like manna? The human spirit hungers for the wisdom of how to live according to the will of God, for knowing what to believe and how to act in ways that find peace with God. Torah, God's self-revelation of God's self and will, is therefore truly bread in the wilderness.
Given this traditional association of manna with the Word of God in the Torah, it is powerful, then, to say that Jesus is the true bread from heaven. Now it is Jesus—the eternal Word made flesh—who is the full revelation of divine communication to the world. To know Jesus, and to receive him as sent by the Father, is to receive the fullness of God's wisdom.
Within this discourse, then, which is first: its wisdom language about eating and drinking, or is it about Eucharist? The best answer seems to be that the discourse is mainly about Jesus being God's Word made flesh, true manna from heaven; and then this Sunday's Gospel joins such an understanding with the Church's practice of Eucharist. It is in our celebration of the Eucharist especially that we encounter Jesus as God's wisdom made flesh for us. As we read further in the Fourth Gospel, we learn this: to accept Jesus as sent by the Father to serve us means that we are to wash one another's feet, to lay down our lives for one another.
Paul, writing to the Corinthians in our Second Reading, has his own way of speaking of the eucharistic body that points in the same direction. First he asserts that the community's sharing in the Body and Blood of Christ—sharing in the one loaf—makes us one body (1 Cor 10:17). A chapter later, (1 Cor 11:29), he says it is absolutely crucial that we “discern the body.” Here, the context makes it clear that he means “body” in two senses: (1) We need to discern that the bread and wine is the presence of the same Lord who died for us; (2) we need to discern that the community of those who share in this worship are themselves one body, requiring that we reverence one another as the body of Christ and attend to one another's needs.
* Ed: The Torah, or Jewish Written Law, consists of the five books of the Hebrew Bible—known more commonly to non-Jews as the "Old Testament"—that were given by God to Moses on Mount Sinai and include within them all of the biblical laws of Judaism. The Torah is also known as the Chumash, Pentateuch or Five Books of Moses. [From the Jewish Virtual Library.]