The behaviour of the believers in Corinth when they gathered on Sunday to worship the Lord was deplorable. Their "love feast" was anything but loving and their holy communion was anything but holy – so much so that Paul said, "your meetings do more harm than good." (1 Corinthians 11:17) There was division among the believers, the "love feast" (a shared meal) was not shared with everyone and, as a result, those who were poor were neglected. To make things worse, there were some who even got drunk! And these were the very people who had come to remember the most loving act the world had ever witnessed – the death of the Lord Jesus Christ for sinners.
Against this background, Paul gives his teaching on the Eucharist: "For I received from the Lord what I also passed on to you: The Lord Jesus, on the night he was betrayed, took bread, and when he had given thanks, he broke it and said, 'This is my body, which is for you; do this in remembrance of me.' In the same way, after supper he took the cup, saying, 'This cup is the new covenant in my blood; do this, whenever you drink it, in remembrance of me.' For whenever you eat this bread and drink this cup, you proclaim the Lord's death until he comes." (1 Corinthians 11:23-26)
I have already written in detail about the words of the Lord at the Last Supper so I'll not repeat myself. However, Paul's words in I Corinthians referring back to that event provide some additional instruction. He says that when we eat and drink the Supper we are proclaiming the Lord's death until he comes. The church is making a statement that we believe Jesus died for us, that he returned to the Father and will return one day for his church. Partaking of the bread and wine "in an unworthy manner" is a reference to the ungodly behaviour that was on display within the church. They were to honour the Lord for what he did for them, symbolised in the bread and wine. Instead, they were dishonouring him. Jesus who gave his body and blood for their redemption and who is the unseen host was being insulted by their behaviour. It showed that they had failed to appreciate that their salvation was purchased at a very high price – the death of God's Son. The consequence, Paul makes clear, was to be "guilty of sinning against the body and blood of Christ." (1 Corinthians 11:27) The way to avoid God's judgement is for each Christian to "examine himself before he eats of the bread and drinks the cup." (1 Corinthians 11:28) Furthermore, Paul says, "For anyone who eats and drinks without recognising the body of Christ eats and drinks judgement to himself." (1 Corinthians 11:29) When Paul speaks here about "the body of Christ", he is referring to the church. (Ephesians 1:22) However tempting it might be to conclude that Paul is teaching that the body of Christ is literally there in the Mass, it is to take the phrase out of context and to misconstrue its meaning. We must not lose sight of the problem Paul was correcting in Corinth. He is not referring to the Catholic teaching of "the real presence" or transubstantiation, but to the unholy behaviour within the body of Christ – the church.
If the believers in Corinth had gathered each Lord's days in a spirit of love, unity and caring then their partaking of the bread and wine would indeed have been holy communion.