Summary: As we take the Lord's supper we are called to examine ourselves, not others. We also need not only examine our sins but also repent from sins and forgive others as we remember His grace that forgives us our sins.
"Examine Yourself before You Take the Lord's Supper" 1 Corinthians 11:23-29
"For I received from the Lord what I also passed on to you: The Lord Jesus, on the night he was betrayed, took bread, 24 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." 25 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." 26 For whenever you eat this bread and drink this cup, you proclaim the Lord's death until he comes. 27 So then, whoever eats the bread or drinks the cup of the Lord in an unworthy manner will be guilty of sinning against the body and blood of the Lord. 28 Everyone ought to examine themselves before they eat of the bread and drink from the cup. 29 For those who eat and drink without discerning the body of Christ eat and drink judgment on themselves."
Have you ever thought about the difference between Christian groups such as Christian Organizations, Christian ministries, Christians clubs, etc., and the churches? You may not have noticed many differences among them. They all have a ministry, worship service, education, fellowship, etc. However, one apparent difference is that the church is composed of the people baptized, while baptism is not required to be a member of other Christian groups. Why is baptism required to be a member of a Church while other Christian groups aren't?
Baptism is a public confession of the commitment to Christ. You need to be baptized to become a member because the church is the body of Christ, each of whose members belongs to Christ and one another. (Rom 1:6 & 12:5)
I would like to share with you today concerning the Lord's supper and the Lord's supper is also required to maintain such commitment and relationship. I hope it may make some sense to you though you may not practice the Lord's supper as often as I hope we do as a church.
When God promised David that one of his sons would succeed him, He also promised that his son would establish his kingdom and build a temple for God. And God also promised a lot of other blessings. God also said, however, if his descendant as a king does wrong, God will punish him with "the rod of men, with the stripes of the sons of men" God was saying He uses human beings to punish him if he disobeys God. In fact, when David committed sins, God inflicted the punishment upon him using his own sons. Can you imagine God using our loved ones as instruments to punish us? Unfortunately, that seems to be the case. It could be your own parents that make your life most difficult, and it could be your spouse or your friend or other church members that make your life miserable. It could be you that makes your parents, your friends sad. Our relationship with our loved ones is such that it could satisfy us most or make us most miserable.
Among many churches described in the New Testament, probably the most troublesome church was the Corinthians church due to the conflict among church members. On the one hand, it was an excellent church in terms of speech, knowledge, spiritual gift, and enthusiasm for the Lord Jesus Christ, but on the other hand, there were factions among members even to the point their meetings did more harm than good. They even took other members to court to resolve their conflict.
I believe this is why you find more emphasis on the church being one body and on love as described in 1 Corinthians 13, where it says, your faith, knowledge, and ministry are in vain without love. Every church in the NT did the Lord's supper. But, the Corinthian church is the only one church Paul had to explain the meaning of the Lord's supper because they totally went against the purpose of the Lord's supper while taking the supper: They didn't share their food with those who didn't have. They didn't care how others might have felt without food. That's why Paul reprimanded them, saying: "do you despise the church of God and humiliate those who have nothing?" (v. 22)
That is why Paul said that they should examine themselves before eating the bread and drinking the cup, the Lord's Supper" (v. 28) Paul didn't say, "examine others", but "examing themselves" because we all are already expert in examining others: getting into others minds, analyzing, judging and even criticizing. That's our nature. That's why Jesus said, "Why do you see the speck that is in your brother's eye, but do not notice the log that is in your own eye?" (Mt 7:3) Do you think Jesus said this to an exceptional group of people? Or Did Jesus make a statement with exaggeration to make a point? Or Do you agree that we see a speck in others yet do not notice the log in our eyes?