A111 : by Tony Garland 
Paul begins discussing the concept of Christ’s “body” in connection with the Lord’s Supper in the previous chapter:
The cup of blessing which we bless, is it not the communion of the blood of Christ? The bread which we break, is it not the communion of the body of Christ? For we, though many, are one bread and one body; for we all partake of that one bread. (1Cor. 10:16-17)
I believe that Paul is teaching by analogy here. The bread primarily represents Christ’s physical body given for us. But it is also true, when we are saved, that we are baptized into His spiritual body (the Body of Christ, 1Cor. 12:13).
In a similar way that individual believers partake of the same physical bread—representing Christ’s physical body broken for them—they also have spiritual unity in fellowship by virtue of being joined together in spiritual Body of Christ, the Church.
The word “communion” (κοινωνία [koinōnia]) could also be translated as “fellowship,” “participation,” (ESV) or “sharing” (NASB, HCSB, NET).
Then, in chapter 11, we read:
For I received from the Lord that which I also delivered to you: that the Lord Jesus on the same night in which He was betrayed took bread; and when He had given thanks, He broke it and said, “Take, eat; this is My body which is broken for you; do this in remembrance of Me.” In the same manner He also took the cup after supper, saying, “This cup is the new covenant in My blood. This do, as often as you drink it, in remembrance of Me.” For as often as you eat this bread and drink this cup, you proclaim the Lord's death till He comes. Therefore whoever eats this bread or drinks this cup of the Lord in an unworthy manner will be guilty of the body and blood of the Lord. But let a man examine himself, and so let him eat of the bread and drink of the cup. For he who eats and drinks in an unworthy manner eats and drinks judgment to himself, not discerning the Lord's body. (1Co 11:23-29)
A careful reading implies that the terms bread and body both refer to Christ’s physical body (which was “broken for you”).
The Lord Himself emphasized that the Lord’s supper was a memorial, in remembrance of Me. Thus, it is a somber and very serious occasion and is not to be undertaken flippantly or as an unbeliever.
When Paul states that those who participate in an unworthy manner are guilty of the body and blood of the Lord, he is indicating that they are taking the elements without understanding or appreciating what they represent—or the price which the Lord paid: the sacrifice of His physical body and blood.
Thus, when eating the bread, they fail to discern that it represents something very holy and costly to God: the broken body of His Son.
In both passages, the bread appears to represent Christ’s physical body. When partaking of the bread in a worthy manner, believers are to discern that which it represents—to see beyond the bread itself in remembrance of what it represents and what it cost (and gained) on their behalf. A failure on the part of the participant to appreciate the deep meaning behind the physical partaking of the bread renders the process of communion unholy and even dangerous. At its worst, it becomes nothing more than routine eating of food and drinking of liquid (which is Paul’s point in 1Cor. 11:21-22).
I continue to thank God that during my many years as an unbeliever, when the rare occasion arose where I was present at a communion service, I was able to discern the seriousness and significance of the event and knew well enough not to partake since I was not His. | 
