I Corinthians 6:2

Do ye not know that the saints shall judge the world? and if the world shall be judged by you, are ye unworthy to judge the smallest matters? (KJV)

Then: Paul didn't like lawsuits which stirred up social unrest (Thiselton, p. 421) inside and outside of the church. Unstated, but addressed by commentators is Corinthian knowledge of the social conditions of civil courts. Paul didn't need to list all that; he wanted to work on motives and solutions. So, instead he twisted their pretzels - sort of and in a good way. Earlier (I Corin. 4:8) he'd crimped their pride by deriding their premature stance of reigning with Christ in judgement. In a rhetorical switch, he lifts up their pride and expects them to get it together and formally judge fellow saints.

Now: We all have days when we can't do anything right. Get in trouble if you do something; get in trouble if you don't do something. The key is the word "unworthy." That gets to feelings and motives. If we speak fairly about the actions of another, and if we first speak directly to the person, all is well. Being fair works in formal courts of law and in personal situations. What doesn't work is speaking for the purposes of personal gain. That usually involves bending or twisting the truth, a highly "unworthy" act.

Jesus taught his disciples that when he sits on the throne, they would judge tribes of Israel. (Matthew 19:18). The conjunction of Paul's and Christ's teachings allow for "great" conversations about whether or not the saints will judge with Christ. Adam Clarke says "no," since Christ probably doesn't need any help. He thinks Christ refers to the a fulfiment of Daniel's prophesy (Daniel 7:18 and 27) in which Christians would take all judgments on earth. Current commentators are more interested in how the "down-to-earth" details of Paul's teaching affected the daily actions of Corinthians (Thiselton, p. 419).

Extra source: The First Epistle to the Corinthians: a commentary on the Greek text by Anthony C. Thiselton (Authentic Media, c2000) online at http://books.google.com/books?id=IHG_DNLpmroC&dq=Corinthians+commentary&printsec=frontcover&source=in&hl=en&ei=6NZZS4ODFpDe8Qba6oDtBA&sa=X&oi=book_result&ct=result&resnum=11&ved=0CDIQ6AEwCg#v=onepage&q=&f=false
Clarke's Commentary - I Corinthians 6; Clarkes Commentary on the Whole Bible by Adam C. Clarke (1760-1762) online at http://www.godrules.net/library/clarke/clarke1cor6.htm