I am the bread of life. Your forefathers ate the manna in the desert, yet they died. But here is the bread that comes down from heaven, which a man may eat and not die. The people grumble at Jesus claim to have come down from heaven. Take a look at v erse 43 .
Belief leads to everlasting life.
Eating the bread from heaven gives eternal life. 54 Whoever eats my flesh and drinks my blood has eternal life, and I will raise him up at the last day. For my flesh is real food and my blood is real drink. 56 Whoever eats my flesh and drinks my blood remains in me, and I in him. Just as the living Father sent me and I live because of the Father, so the one who feeds on me will live because of me.