Actually, the non Catholic position is the premise that must be proved, as it is the rejection of what the universal Church has held as firm belief since the beginning.
First, there is no evidence that Jesus ate of the bread which He gave to the Apostles or that He drank of the wine in the cup which He gave them.
Second, we must take into account ALL the words Jesus spoke regarding this subject, all of which are unflinchingly supportive of the Catholic belief in the actuality of Christ’s body and blood in the Eucharist.
Third, we must consider the story of Ezekiel and the eating of the scroll which the Lord gave him. The story is similar to what Jesus says of His flesh, that those who ate of it would never be hungry.
Fourth, we see that the first Christians regularly shared in the breaking of the bread and that bread was not just ordinary food. Some of it was reserved and taken to those who were not present.
So we see that there is abundant support for the Catholic belief from the OT, the NT and the early writings of the those who learned from the Apostles themselves.
It's only the position that the Catholic church has had from the beginning, not the *universal* church. So it's only rejection of Catholic teaching, not rejection of Scripture or Jesus.
That is absurd,. Regardless of the autocratic nature of Rome, what she deemd as true does not make it so. What Church fathers believed on the Eucharist has little weight, as they were in error about some other things as well, and both are judged by Scripture as supreme.
And indeed , we must take into account ALL the words Jesus AND the rest of Scripture spoke regarding this subject, all of which are NOT unflinchingly supportive of the Catholic belief in the actuality of Christ’s body and blood in the Eucharist, but best support the language as allegorical .
The use of metaphors and the contrast between the earthly and the spiritual, and the concept of believing as being what obtain life, and as being the means which one is to live by, is consistent with what John teaches.
In John 1:29, He is “the Lamb of God, which taketh away the sin of the world.”
In John 3, Jesus is the likened to the serpent in the wilderness (Num. 21) who must “be lifted up: That whosoever believeth in him should not perish, but have eternal” (vs. 14, 15).
In John 4, Jesus is the living water, that “whosoever drinketh of the water that I shall give him shall never thirst; but the water that I shall give him shall be in him a well of water springing up into everlasting life” (v. 14).
In John 5, Jesus is the Divine Son of God “making himself equal with God”, and the prophesied Messiah (vs. 18, 39).
In John 6, Jesus is the bread of God “which cometh down from heaven, and giveth life unto the world.” “..that every one which seeth the Son, and believeth on him, may have everlasting life: and I will raise him up at the last day” (vs. 35,40). This bread is called His flesh, “which I will give for the life of the world” (v. 51). And as He is the “living bread,” and “the life of the flesh is in the blood,” so the soon to be crucified Christ is metaphorical bread and blood.
In John 10, Jesus is “the door of the sheep,”, and the good shepherd [who] giveth his life for the sheep”, “that they might have life, and that they might have it more abundantly” vs. 7, 10, 11).
In John 12, He is the LORD who Isaiah saw high and lifted up in glory, when Isaiah uttered the prophecy which as given in it’s fulfilled sense in Jn. 6 (Is. 6:1-10; Jn. 12:34b-50). To God be the glory.
In John 15, Jesus is the true vine.
Moreover, Contextually, the LORD is speaking to Jews and the Jews (and Greeks, which influenced Jews during the time of Christ, and whose language was common) were well acquainted with the use of symbolic language, with the O.T. often speaking of eating in a figurative manner.
*When the fearful Israelites exclaimed that the Promised Land was “a land that eateth up the inhabitants thereof,”
* or when Joshua exhorted the Israelites, “Only rebel not ye against the LORD, neither fear ye the people of the land; for they are bread for us” (Num. 13:32; 14:9), it is not to be supposed that the land or the Israelites would become cannibals.
* And when Jeremiah proclaims, Your words were found. and I ate them. and your word was to me the joy and rejoicing of my heart" (Jer. 15:16),
* or Ezekiel is told, "eat this scroll, and go, speak to the house of Israel" (Ezek. 3:1),
* or (in a phrase most similar to the Lord's supper) John is commanded, "Take the scroll ... Take it and eat it" (Rev. 10:8-9 ), then it is not speaking of literal eating.
* And it is certain that cannibalism was not looked upon favorably in Israel, and is only portrayed negatively, even metaphorically, as David declared, "When the wicked, even mine enemies and my foes, came upon me to eat up my flesh, they stumbled and fell." (Psa 27:2)
Thus the use of metaphors in Jn. 6 to denote believing and living by the Word of God, and most essentially Christ, is consistent theologically, culturally and and grammatically, whereas eating something to gain eternal life is distinctively pagan. The Jewish passover did not impart life, and Jesus analogy in Jn. 6 was not to the passover, but the miraculous bread from Heaven, which gave physical life, which corresponds to spiritual life under the New Covenant.
Third, we must consider the story of Ezekiel and the eating of the scroll which the Lord gave him. The story is similar to what Jesus says of His flesh, that those who ate of it would never be hungry.
That is eating one of my points; the eating of the scroll was also allegorical, (Ezek. 3:1-3) as that of the book in Rv. 10:9,10) and in other places, as was the Lord's "meat" in Jn. 4:24, and believers life by Christ as He lived by the Father. (Jn. 6:57) And nowhere does eating physical food satisfy spiritually.
In addition is the absurdity that the apostles would passively consume real blood and human flesh, which they had to understand it was, without the usual questioning in such a context, such as Peter exampled when called to eat unclean flesh. But conspiratorialitists also have answers for everything
Fourth, we see that the first Christians regularly shared in the breaking of the bread and that bread was not just ordinary food. Some of it was reserved and taken to those who were not present.
Where do you see that?! It should be obvious that the church was coming together to communally eat in one place, but as in Acts 6, some were going hungry while others feasted - in complete contradiction to the Lord's unselfish death. Therefore to avoid this disparity due to the selfishness of some, and rather than taking food to those who did not come to the assembly, they were instructed to eat their own normal supper at home if they were hungry before they came to the communal sharing of bread, and to wait for each other when they did. Nothing is said about taking food out.
"When ye come together therefore into one place, this is not to eat the Lord's supper. For in eating every one taketh before other his own supper: and one is hungry, and another is drunken. What? have ye not houses to eat and to drink in? or despise ye the church of God, and shame them that have not? What shall I say to you? shall I praise you in this? I praise you not. " (1 Corinthians 11:20-22)
"Wherefore, my brethren, when ye come together to eat, tarry one for another. And if any man hunger, let him eat at home; that ye come not together unto condemnation. And the rest will I set in order when I come. " (1 Corinthians 11:33-34)
The Lord's supper itself was part of a larger sharing of food, and Jude speaks of the believers "feast of charity," and of which your sanctioned notes state: which were associated with eucharistic celebrations at certain stages of early Christian practice; cf. 1 Cor 11:18–34 and the note on 2 Pt 2:13. (http://usccb.org/bible/scripture.cfm?bk=Jude&ch=#73001012-1)
So we see that there is abundant support for the Catholic belief from the OT, the NT and the early writings of the those who learned from the Apostles themselves.
Rather, what we see is more RC eisegesis, reading into texts what is not there, and in other passages excluding any other interpretation other than Romes, even though allegory is what is most supported. Do not claim you are being objective, as you are not and you cannot if you will defend Rome.