What does John 6:33 mean?
After Jesus claims that eternal life is found in belief, not in good works (John 6:27–29), the people demand a miraculous sign. This crowd was attracted to Jesus through His healing miracles and His spectacular feeding of more than five thousand the day before (John 6:2; John 6:9–14). Even so, they resist when Christ points to faith, not actions, as the source of salvation. Invoking Moses and the provision of manna (Exodus 16), they challenge Jesus to prove Himself.Instead, Jesus reminds the people that miracles come from God, not men. In the same way, eternal life comes from God and not from men, even great men like Moses. And it certainly cannot come from men performing good works. The "true bread from heaven" is Christ Himself. Jesus is stating, in unambiguous terms, that God requires man to believe in Him in order to see eternal life.
Later, declarations that He has come "from heaven" will be used as evidence against Jesus, by those who claim He is a blasphemer (Matthew 26:65). More immediately, Jesus' claim to be the bread of heaven will be the source of complaining. For now, though, the people are still thinking from a material, earthly perspective. And so, once again, they will ask Jesus to provide them with the bread He is speaking of.