The problem was that in the feast of charity, which was an actual communal meal, some members of the body were being treated like lepers:
"When ye come together therefore into one place, this is not to eat the Lord's supper. {21} For in eating every one taketh before other his own supper: and one is hungry, and another is drunken. " (1 Corinthians 11:20-21)
Paul's criticism of them is that they are really not commemorating the Lord's unselfish sacrifice of Himself due to the selfish manner in which they are practicing it.
He then states the instructions given in instituting the supper, and that "as often as ye eat this bread, and drink this cup, ye do shew [manifest] the Lord's death till he come." {26}
Christians manifest His death for them by death to self in serving God and therefor others. Thus they were not manifesting recognition of Jesus death for them because they were not caring for the life of others. And because as often as ye eat this bread, and drink this cup, ye do shew [manifest] the Lord's death till he come," therefore the next verse says,
"Wherefore whosoever shall eat this bread, and drink this cup of the Lord, unworthily, shall be guilty of the body and blood of the Lord. {28} But let a man examine himself, and so let him eat of that bread, and drink of that cup. {29} For he that eateth and drinketh unworthily, eateth and drinketh damnation to himself, not discerning the Lord's body. " (1 Corinthians 11:27-29)
Examining primarily concerns how you were treating each others, which recalls Jesus words about being reconciled before offering sacrifice, (Mt. 5:23,24) But there is nothing in here about the composition of the physical bread they ate, but not discerning or judging the "Lord's body" refers to either effectively denying what His death represents by their selfishness, as per v. 20 - "this is not to eat the Lord's supper" - or by failing to recognize the other members as part of the body and to them justice according.
Paul next reveals that this miscelebration was the reason that they were being chastened and judged, including death, which capital punishment for lack of care is consistent with O.T. penalty about not caring for the poor. (Ex. 22:22-24)
In further confirmation that this was the issue, Paul provides the remedy needed to avoid chastening, which was not by recognizing that the bread was really Jesus flesh, but by rightly judging what the sacrifice of Christ which they commemorated represented and acting accordingly; "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) "
This corresponds to what Paul said in the previous chapter, that "For we being many are one bread, and one body: for we are all partakers of that one bread. " (1 Corinthians 10:17) For the body of Christ to be in communion with Jesus broken body and shed blood in His death is to be communally consistent with Him who died for us and purchased us with His blood.
"For the love of Christ constraineth us; because we thus judge, that if one died for all, then were all dead: {15} And that he died for all, that they which live should not henceforth live unto themselves, but unto him which died for them, and rose again. " (2 Corinthians 5:14-15)
In the next chapter Paul further elaborates on the interdependence of the body, For as the body is one, and hath many members, and all the members of that one body, being many, are one body: so also is Christ." "That there should be no schism in the body; but that the members should have the same care one for another." (1Cor. 12:12,25)
And how superficial we are in this today. go.
[20]When you come therefore together into one place, it is not now to eat the Lord's supperYou are right in verse 20, St. Paul reprehends the abuses of the Corinthians;
[21] For every one taketh before his own supper to eat. And one indeed is hungry and another is drunk
[22] What, have you not houses to eat and to drink in? Or despise ye the church of God; and put them to shame that have not? What shall I say to you? Do I praise you? In this I praise you not.
[23] For I have received of the Lord that which also I delivered unto you, that the Lord Jesus, the same night in which he was betrayed, took bread.
[24] And giving thanks, broke, and said: Take ye, and eat: this is my body, which shall be delivered for you: this do for the commemoration of me.
[25] In like manner also the chalice, after he had supped, saying: This chalice is the new testament in my blood: this do ye, as often as you shall drink, for the commemoration of me.
[26] For as often as you shall eat this bread, and drink the chalice, you shall shew the death of the Lord, until he come.
[27] Therefore whosoever shall eat this bread, or drink the chalice of the Lord unworthily, shall be guilty of the body and of the blood of the Lord.
[28] But let a man prove himself: and so let him eat of that bread, and drink of the chalice.
[29] For he that eateth and drinketh unworthily, eateth and drinketh judgment to himself, not discerning the body of the Lord.
[30] Therefore are there many infirm and weak among you, and many sleep.
[31] But if we would judge ourselves, we should not be judged.
[32] But whilst we are judged, we are chastised by the Lord, that we be not condemned with this world.
[33] Wherefore, my brethren, when you come together to eat, wait for one another.
[34] If any man be hungry, let him eat at home; that you come not together unto judgment. And the rest I will set in order, when I come.
[16] The chalice of benediction, which we bless, is it not the communion of the blood of Christ?Here Paul states that because the bread is one, all we, being many, are one body, who partake of that one bread
And the bread, which we break, is it not the partaking of the body of the Lord?
[17] For we, being many, are one bread, one body, all that partake of one bread
[26] And if one member suffer any thing, all the members suffer with it; or if one member glory, all the members rejoice with it.
[27] Now you are the body of Christ, and members of member.
[28] And God indeed hath set some in the church; first apostles, secondly prophets, thirdly doctors/teachers; after that miracles; then the graces of healing, helps, governments, kinds of tongues, interpretations of speeches.
[29] Are all apostles? Are all prophets? Are all teachers/doctors?
[30] Are all workers of miracles? Have all the grace of healing? Do all speak with tongues? Do all interpret?
It is true that the Lord's supper passage in 1 Cor. 11 is in the context of the Chruch being one body. It establishes indeed that the Sacrfiice of the Mass is necessarily a community-building sacrament, one that defines the body of the Catholic Church as it exists in the local parish. However it does so precisely because there is a sacrifice of Christ that is at the center of the sacrament. It "shows the death of Jesus", -- it is, therefore, a sacrament rather than a memorial meal. It then is scripturally without warrant to read the phrase "discerning the body" as referring to the body of the believers. The immediate context is death of Jesus; the immediate scriptural reference is the words of consecration, "this is my body", in the synoptic gospels, that St. Paul repeats. The "body" of 1 Cor. 11:29 is then that very body shown the disciples in the appearance of bread: Jesus's.
This passage is not fully understood unless the doctrine of the real presence is understood, most fully taught in John 6.