I don’t think you are serious, just anti-Catholic.
Like Purgatory and the Trinity, Transubstantiation is a word that explains the words of Jesus. This is My Body and this is My Blood. You have already admitted that you do not believe. You do not accept the words of Jesus, as “you have no life in you” (John 6:53).
Transubstantiation is the Catholic doctrine that, at the consecration during Mass, the bread and wine truly become the Body and Blood of Jesus Christ, even though their appearances (or “accidents”) remain unchanged.
This teaching is rooted in Scripture, especially 1 Corinthians 11:23-29, where St. Paul recounts Jesus saying, “This is my body... This cup is the new covenant in my blood.” The Church understands these words literally, meaning the substance of bread and wine is transformed into Christ’s glorified, resurrected Body and Blood (1 Cor 15:42-44; John 20:27).
The Council of Trent clarified this mystery, affirming that the change is real though not visible (Catechism of the Catholic Church, 1376-1377). Thus, the Eucharist is not symbolic but the true presence of Christ.
I do not believe Rome's understanding of the passages in question.
You and all Roman Catholics have to adjust your exegesis mid-stream in John 6.
One part is literal and one part is metaphysical.
I've asked other Roman Catholics if they get hungry or thirsty.
In John 6 He said you wouldn't get hungry or thirsty. RCs try to spiritualize these questions while then turning around and trying to hold to a literal rendering of the remaining passage all the while negating the beginning of the passage where Christ speaks of the necessity of believing in Him.
That's how He opened the discussion with the Jews.
26Jesus answered them and said, “Truly, truly, I say to you, you seek Me, not because you saw signs, but because you ate of the loaves and were filled. 27“Do not work for the food which perishes, but for the food which endures to eternal life, which the Son of Man will give to you, for on Him the Father, God, has set His seal.” 28Therefore they said to Him, “What shall we do, so that we may work the works of God?” 29Jesus answered and said to them, “This is the work of God, that you believe in Him whom He has sent.
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They don't understand what He's saying. They, like Roman Catholicism, thinks He's discussing actual bread. The unbelieving Jews and Roman Catholicism have made the same error.
30So they said to Him, “What then do You do for a sign, so that we may see, and believe You? What work do You perform? 31“Our fathers ate the manna in the wilderness; as it is written, ‘HE GAVE THEM BREAD OUT OF HEAVEN TO EAT.’” 32Jesus then said to them, “Truly, truly, I say to you, it is not Moses who has given you the bread out of heaven, but it is My Father who gives you the true bread out of heaven. 33“For the bread of God is that which comes down out of heaven, and gives life to the world.” 34Then they said to Him, “Lord, always give us this bread.
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In this passage Jesus identifies Himself as the bread of life. He also promises eternal life to those who believe; He will lose none that the Father gives Him...it's a clear statement of the security of the believer...which Roman Catholicism denies.
35Jesus said to them, “I am the bread of life; he who comes to Me will not hunger, and he who believes in Me will never thirst.
36“But I said to you that you have seen Me, and yet do not believe. 37“All that the Father gives Me will come to Me, and the one who comes to Me I will certainly not cast out. 38“For I have come down from heaven, not to do My own will, but the will of Him who sent Me. 39“This is the will of Him who sent Me, that of all that He has given Me I lose nothing, but raise it up on the last day. 40“For this is the will of My Father, that everyone who beholds the Son and believes in Him will have eternal life, and I Myself will raise him up on the last day.”
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As noted before Paul recorded exactly what he received from the Lord....and it did not include transubstantiation.
It's not about salvation as one must already be a believer to participate in the Lord's Supper.
We do this to proclaim His death until He comes. The text is crystal clear.
"26For as often as you eat this bread and drink the cup, you proclaim the Lord’s death until He comes." 1 Cor 11:26 NASB