Paul wants the Corinthians to see how strange their behavior is. Believers were carrying their quarrels to unbelieving courts, as if no one in the church could settle them. Barnes says the point of this verse is to show that "Christians were qualified to determine controversies which might arise among themselves." The first question reminds them of something they should already know: the saints shall judge the world. The second question draws the conclusion. If something as great as the world will be judged by them, how could they be unfit to handle "the smallest matters"? Barnes explains these small matters as lawsuits over property and similar things.

The Corinthians' reply is not recorded, but the expected answer is plain: no, they are not unworthy. Paul presses the same point further: "Know ye not that we shall judge angels? how much more things that pertain to this life?" (1 Corinthians 6:3). He then tells them to set even those "least esteemed in the church" to judge such matters (1 Corinthians 6:4), and adds, "I speak to your shame" (1 Corinthians 6:5).

Paul calls the courts the believers were using "the unjust" (1 Corinthians 6:1) and "the unbelievers" (1 Corinthians 6:6). Barnes explains that these were pagan courts, run by unbelievers rather than saints. The word translated "unworthy" is anaxioi, meaning not fit or not worthy. The word behind "matters" is kritērion, which Thayer defines as a tribunal or court, and also as the case or suit to be decided. It appears only three times in the New Testament: here, in 1 Corinthians 6:4, and in James 2:6, where rich men "draw you before the judgment seats."

Paul measures a small dispute against a large future. Barnes notes that this verse has been read many ways. The common reading, which he credits to Calvin, Beza, Grotius, and others and accepts as "the true interpretation," is that at the last judgment Christians "will in that day be employed in some manner in judging the world." Barnes points to Jesus' promise that the apostles would sit on thrones "judging the twelve tribes of Israel" (Matthew 19:28; Luke 22:30). Gill reads it differently. He takes Paul to mean that before long Christians would hold civil office and "sit upon the benches of judges."

Either way, Paul's argument holds. People whom God is preparing for a great responsibility should be able to handle a small one now. What believers will one day be should shape how they treat one another today.