v1: Disputes amongst the people of Israel were to be settled by the Levites. In a similar way, in the Church, disputes were to be settled within the Church. Some had taken their disputes to legal courts, "before the ungodly for judgment".

This implies that both parties would be submissive to the decision of the church leaders. It implies also that the leaders are godly and wise.

v2-3: Again, the Corinthians knew about judging angels in the life to come, see 5.12. Should they not also be competent to judge those in the church now?

v4: The effect of seeking justice outside the church was that "men of little account" in the church are given authority in the lives of Christians.The NIV Margin is better here, “Therefore ... do you appoint as judges men of little account in the church?”

v5-6: A further challenge; was there not a man in the church wise enough to deal with such issues? Again, Paul's implication is that there was a lack of spiritual maturity. In the absence of such a man, one brother takes another to court.

v7-8: Legal actions frequently relate to "rights" or to "greed"; the Lord Jesus was abused by human courts, 1 Pet 2.23; 1 Tim 6.13.

How sad when Christians insist on their own rights to the hurt of others. It is better, says Paul, to be defrauded and cheated, rather than to pursue a legal claim outside the church. The Lord Jesus suffered unfairly, and we must expect the same.

v9-10: Serious and persistent sins; those who cling to such things "will not inherit the kingdom of God"; they are unrighteous, not believing in Christ, as in Gal 5.21.

Paul refers to "swindlers" (extortioners); perhaps someone was guilty of this, see v7, 5.11. Others were guilty of sexual sins, which Paul spoke of in ch 5; but other sins were also serious, and no Christian in the church should continue in such sins.

v11: These sins had characterised the Corinthians before they were converted to Christ. Since they had been washed, sanctified, justified, they must reject these things; it is unacceptable to return to the old ways. (Lev 20.26; 1 Pet 2.9; Heb 10.10; 13.12; 1 Thess 4)

Remember, many of these folk will have lived lives that by biblical standards were plainly wicked. Paul lists out some of the people who had come to faith in Corinth and been added to the church: If the Lord answers our prayers, we must expect him to add such people to our number.

We mustn’t misunderstand Paul’s last sentence. Was Paul saying that these converts had left behind their previous sins completely? Clearly not. If they had, he wouldn’t have needed to give them that warning. When he tells them not to be deceived, it’s because some believed that they could return to their old sins and still inherit the kingdom of God. Paul goes on to explain that consorting with prostitutes is unthinkable for those who are united with Christ (vv. 13–20). Why did he need to spell it out? Because some had never grasped that simple fact. (Stephen Rees in Evangelical Times, Sept 2023.) 

v12: Our behaviour is to be governed by Scripture; certain things are clearly prohibited, they are wrong for the Christian; other things are "permissible" (or lawful), but are not "beneficial" (or helpful); such things can master us, bring us into bondage, bring us under its power.

The enemy will use the ordinary desires that we have, or ordinary things that we come into contact with, to restrict our effectiveness for Christ; e.g: physical desires, hobbies and pastimes, employment and career, family. The danger is that such lawful things will divert us from the best things.

It seems that Paul was quoting another author, "everything is permissible for me"; there is a danger that we can use such statements to condone sinful behaviour.

v13: Although physical things will not last, since God will destroy them, they can still cause us to sin. Corinth had a reputation throughout Greece as the centre of immorality and prostitution; this would have brought extra temptation for the Christians. In different circumstances, other temptations will arise.

Paul quotes a local proverb here; 'part of the implication of this belief was that sex had no more then a physical effect and that illicit sex was the equivalent of several good meals.' (David Devenish, Demolishing Strongholds)

v14: Look forward to our physical resurrection (ch 15; Eph 1.19-20); the temptations relating to our body, esp. sexual temptations, will cease one day. However, this does not exempt us from resisting temptation.

v15-16: Being joined to the Lord is an enormous privilege; it is consequently extremely serious for a Christian to become "one flesh" with a prostitute.

Twice Paul asks, "Do you not know...?" What is being practised is wrong; and the Christian must flee immorality.

'Casual sex, intimacy outside of marriage, pulls the Corinthian ploy. It pretends we can give the body and not affect the soul. We can’t. Sex apart from God’s plan wounds the soul.' (Max Lucado, It's not about me.)

In light of sexual sin, Paul does not refer to a breach of the seventh commandment. Rather he insists on the new covenant, which the member had departed from.We are‘members of Christ.’ 

v17: We are "one spirit" with Christ; our behaviour must match this, for He is jealous.

v18: Sexual immorality is particularly serious, as it a sin against a person's own body. We can take Joseph as our example of one who fled from sexual immorality. In contrast, the list of Bible characters who fell into sexual sin is long; the effects in their lives demonstrate the damage that such sin can bring. In Num 25.1-3, Israel fell into sexual sin; the false prophet Balaam had been unable to effectively curse Israel, but sexual sin proved destructive.

v19-20: Again, privilege and responsibility, do you not know? See Deut 14.1-2. We are washed, sanctified, justified and in-dwelt by the Spirit of God; we are therefore secure in God.

The "temple" refers to the Holy of Holies, the place of communion with God, and the enjoyment of a relationship with God. The motivation is not whether we breach the seventh commandment, but whether we respect the temple of God – this is new covenant thinking!

We are bought at the price of the life of the Lord Jesus Christ, the Son of God. The illustration here is of a slave, bought by one to whom he now belongs, "you are not your own". A slave involuntarily gave over his time, his family, his decisions, his plans; we too must give over such things to God. Our aim must be to glorify the One to whom we belong. Since our body is a temple, we must carefully and ruthlessly put away those things that would defile.

These verses teach the positive and negative aspects of discipleship; giving ourselves entirely to Him, and avoiding those things which defile. These verses also prefigure the teaching of chapter 15, concerning the resurrection of the body. They also stand against the Greek thinking that the body was unimportant and essentially bad.