Read the entire chapter six of John. Then read the first few verse in John 3, up through verse sixteen and seventeen. There is a common thread to those sections of John's Gospel. Jesus is teaching that salvation, being born from above, is by believing in Him. Nothing else. Baptism is an outward sign that you have taken the death of Christ as your propitiation and the Risen Christ as your eternal promise.
In John 3 Jesus explains the vital lesson of healing via the brass Serpent Moses placed upon a pole, to deal with the poisonous snake bites. The Jews, being prone to literal foolishness --like thinking eating Jesus gets God's life in them is what He was teaching, so they turn from following Him-- were so blind that a few generations into the Promised land and the Jews were making brass snakes and worshipping the idols! Jesus taught Nicodemus that it was the belief that they would be healed that allowed looking at the Brass snake to get healing! Jesus did not teach Nicodemus that the actual brass snake healed the people bitten.
Moving on to John 6, Jesus sets the stage for this crucial lesson of 'by faith do you have eternal life', by first miraculously turning a few loaves and fishes into a huge repast for thousands. That is the displayed Power of God to do the Miraculous.
Then, He tells the folks who pursued Him to the other side of the lake that they were running after Him not for the Life God is sending to them from Heaven, Life in Jesus by God The Father Almighty, they were running after Him because they had witnessed a great sign and eaten miraculously provided food which filled their stomachs not their souls. This Jesus dealt with using sarcasm.
He did that sarcasm thing on special occasions to shut off the foolishness of yada yada yada Jews were prone to engage in when they should instead look for spiritual truth. [John 6:32 Jesus therefore said to them, "Most certainly, I tell you, it wasn't Moses who gave you the bread out of heaven, but my Father gives you the true bread out of heaven.] Jesus just told them two crucial clues: 1. it was God Who provided the manna/bread from Heaven in the desert; 2. Jesus is the true bread from Heaven as contrast to the belly bread in the desert ... thus He differentiated the manna/bread given by God in the desert with the real life giving SPIRITUAL Bread Who is Jesus The Christ. If Jesus had meant He is also physical bread to be eaten and run through to the draught bread, He would not have contrasted real manna with Himself, instead he would have explained it as the same.
[ John 6: 33 For the bread of God is that which comes down out of heaven, and gives life to the world."] This is Jesus sarcastically telling them that the real bread form Heaven is a person, not manna, and this person gives life to the world. Have catholics forgotten that it was the entire of Creation which fell cursed with the fall of Adam and Eve, thus Jesus reconciled more than just human spirits to God, He came from Heaven and gave Himself the perfect propitiation sacrifice in order to redeem ALL OF CREATION, cats and rats and elephants aren't eating Jesus and drinking His blood yet they are being reconciled to the Father God via The Cross of Christ, the Shed Blood of The Christ!
And finally, let the ones who were present when Jesus taught this show you the meanings: John 6: 27 "Don't work for the food which perishes, but for the food which remains to eternal life, which the Son of Man will give to you. For God the Father has sealed him." 28 They said therefore to him, "What must we do, that we may work the works of God?" The Jews listening knew He was teaching about something other than the breads and fishes and miraculous expansion to feed thousands. They heard what he was teaching, 'don't work for the food which perishes' ... that's bread and wine, which do spoil. Their response was focused upon work not foods, because they knew He referred to something other than the bread and fishes of the recent miracle!
When the Jews asked 'what work must we do' Jesus told them plainly, "The work of God is to believe on Him Whom God has sent." The entire lesson in John 6 is about 'what must I do to be saved?'.
The Passover was only days away then. If He had established a cannibalistic rite as a new covenant then at Passover, why would He be so plain teaching these eager Jews that believing on Whom God Has sent is the work, the Real work, the Only work that God requires for eternal life? ... And the catholics said, oh yeah, He would have told them then that they had to eat his flesh and drink His blood to get God's Life in them. And he did, can't you read what the Bible clearly says? and God will say to them, 'Depart from me. I never knew you because you spurned my commandment to all their generations to never ever eat the blood because the life of the creature is in the blood and I offered to you eternal Life, not creature life.'
ping to the John 6 apologetics
I stopped reading right there; it tells me all I need to know about personal Protestant theology.
A lot of verbiage to deny the plain words of our Lord. When some of his disciples understood him as speaking literally and departed Jesus did not correct them. When Jesus challenged the apostles and asked if they would leave too, Peter did not respond with “Oh, I get that you are speaking metaphorically. What rubes are those who left.” The length some people will go to deny God’s words when they do not match their human understanding!