Read John 6:51-58
51I am the living bread that came down from heaven. If anyone eats this bread, he will live for ever. The bread that I will give him is my flesh, which I give so that the world may live.”
52 This started an angry argument among them. “How can this man give us his flesh to eat?” they asked.
53 Jesus said to them, “I am telling you the truth: if you do not eat the flesh of the Son of Man and drink his blood, you will not have life in yourselves. 54Those who eat my flesh and drink my blood have eternal life, and I will raise them to life on the last day. 55For my flesh is the real food; my blood is the real drink. 56Those who eat my flesh and drink my blood live in me, and I live in them. 57The living Father sent me, and because of him I live also. In the same way whoever eats me will live because of me. 58This, then, is the bread that came down from heaven; it is not like the bread that your ancestors ate. They later died, but those who eat this bread will live for ever.”
Jesus continues to tell the people the mystery of how his broken body and shed blood can sustain them.