What does John 6:57 mean?

During this discourse, Jesus has explained how He is the "true bread from heaven" (John 6:32–33). Earlier miracles from God such as manna (Exodus 16) symbolized this very meaning. According to Jesus, only those who believe in the One sent by God can have eternal life. The miraculous bread of manna, like the miraculous bread Jesus had just created the day before (John 6:9–14), were not the ultimate point of God's message. Rather, they were meant to point to something eternal.

This eternal meaning points to an intimate relationship. Food for the body must be taken inside, by eating it, for it to do the body any good. Belief in Christ is something which a person must take "inside" themselves; this is symbolized by the role of Jesus as the Bread of Life. The prior verse used the Greek root word menō, which carries a sense of enduring, dwelling, or persisting. This same word is used to describe the relationship of the divine Father and Son, as well as Christ with those who believe in Him (John 14:10; 15:4).

Here, Jesus connects the idea of this "abiding" relationship to the source of eternal life, which He earlier described as coming through belief. Jesus previously emphasized that "the bread that comes down from heaven" is embodied in this physical person (John 6:35), whom God expects people to accept if they want to be "raised up" (John 6:29, 39–40). The concept of "feeding" on Jesus, then, is meant to continue this symbolism: taking Christ into one's life in the most complete, deep, and full sense.