I’ve never seen a Protestant rebuttal to John 6:51-58.
I imagine such would not, could not, be succinct, would be lengthy and convoluted, and I would get a headache trying to understand it.
Are you familiar with osmosis? How about entropy?
Our Savior was, is, and will forever be Divine.
The Divine was created into the temporal.
Here in the temporal creation, everything touches everything else. You are breathing oxygen atoms breathed by Einstein, Washington, and even Jesus.
He was pretty much literally torn to shreds, the equivalent of a human food processor, to spread his Divine flesh and blood upon, and throughout the WHOLE EARTH.
Not just the lil wafers, and wine in only your cup.
The WHOLE WORLD!
Every meal is communion, or it should be. He came to SAVE the world. Jesus doesn't go into hiding in the Popes kitchen pantry away from the sinners.
I doubt you'll understand it, but here goes:
"John 6:61 Aware that his disciples were grumbling about this, Jesus said to them, Does this offend you?
62 Then what if you see the Son of Man ascend to where he was before!
63 The Spirit gives life; the flesh counts for nothing. The words I have spoken to youthey are full of the Spirit and life.
64 Yet there are some of you who do not believe. For Jesus had known from the beginning which of them did not believe and who would betray him.
65 He went on to say, This is why I told you that no one can come to me unless the Father has enabled them.
Jesus was speaking figuratively! If the flesh counts for nothing, then the consumption of food while in the flesh also counts for nothing. It is Spiritual.
John uses the word "believe" 46 times, and John 3:16 summarizes the gospel perfectly.
Since the doctrine of transubstantiation is such a critical issue, there must be several elaborations of it in scripture, but this is the only one that gets used as proof of doctrine. Are there others?
Incidentally, if a Christian has only taken communion once in a non-catholic church, does it satisfy the passage you quoted?
Augustine: “Believe, and thou hast eaten”