In this chapter Paul continues the theme of how believers are to properly judge one another in the church. He does this by; first shaming those who don’t judge (for they will even judge angels), and secondly by warning those who live cavalierly of the shaky ground they are on:
“Does any one of you, when he has a case against his neighbor, dare to go to law before the unrighteous and not before the saints? 2 Or do you not know that the saints will judge the world? If the world is judged by you, are you not competent to constitute the smallest law courts? 3 Do you not know that we will judge angels? How much more matters of this life? 4 So if you have law courts dealing with matters of this life, do you appoint them as judges who are of no account in the church? 5 I say this to your shame. Is it so, that there is not among you one wise man who will be able to decide between his brethren, 6 but brother goes to law with brother, and that before unbelievers?
7 Actually, then, it is already a defeat for you, that you have lawsuits with one another. Why not rather be wronged? Why not rather be defrauded? 8 On the contrary, you yourselves wrong and defraud. You do this even to your brethren. 9 Or do you not know that the unrighteous will not inherit the kingdom of God? Do not be deceived; neither fornicators, nor idolaters, nor adulterers, nor effeminate, nor homosexuals, 10 nor thieves, nor the covetous, nor drunkards, nor revilers, nor swindlers, will inherit the kingdom of God. 11 Such were some of you; but you were washed, but you were sanctified, but you were justified in the name of the Lord Jesus Christ and in the Spirit of our God.”
First, Paul uses an “a fortiori argument” (from the lesser to the greater, or with greater force all the more) in order to point out the gravity of what’s occurring with believers, namely they are “suing each other”.
These whom the apostle calls; “saints” are acting like “aint’s”. Those whom Paul describes as “called” are living like the “not called”. Their inability to properly make judgments within the church (Chapter 5) spills over into the court of a heathen judge. Their moral ineptness to make righteous distinctions was lamentable and occurred because of their ignorance regarding final salvation (e.g., the future judgment of angelic beings and the world they were to execute). Thus, if the forthcoming judgments are weightier, these present judgments should be much simpler. But for them it was not the case.
Paul here seems to undermine (perhaps mock) their (lack of) “knowledge and wisdom” about ultimate issues and say something that may seem to be contradictory. In chapter 5:12-13 Paul says that believers judge insiders and God judges outsiders: “For what have I to do with judging outsiders? Do you not judge those who are within the church? 13 But those who are outside, God judges,” yet in chapter 6:2 he says that believers will judge the world.
If world means angelic and human beings (v.3)—supporting said notion, then the issue is not if, but when we are to judge these beings—in the future. Thus, presently, we are to focus on our own, God will deal with the non-believer. But I’m still puzzled about future judgement.
Presently we are judging whether or not something is in accord with godliness or not, whether it is sinful or righteous. In the future, sin will be no more, so what then will we judge? I think the answer is that we will judge not over what is righteous or wicked, but on how righteousness will inform our distinctions (e.g. the wiser way to rule and reign perhaps?).
That is, the present judgments we are to presently make have a moral texture to them. Distinguishing between what is good and evil. However, in the future (in the new heaven and the new earth) these judgments will have an application to righteousness alone, for the former world of sin death and corruption will be no more.
I think this makes sense because God is the fountain and eternal source of just judgments before creation and after it. As the redeemed creation and community of God, in the future there will no longer be slavery to wickedness, only the freedom to make righteous judgments. I’m aware of the weightiness and nuanced intricacies of the aforesaid, but that seems to me a reasonable view. So, Paul uses an argument from the lessor (i.e., judge among yourselves) to the greater (i.e., since, or because you will judge angels and the world).
Second, Paul shames the Corinthians because of their ignorance (i.e., they are the redeemed community of God the Righteous Judge) and subsequent ungodly dealings with one another. These people thought more highly of themselves then they should have, blinded by their own pride, instead of being wronged or defrauded, they executed lawsuits against each other before unrighteous judges. Both parties (the perpetrators and the victims) were guilty of unrighteousness according to the apostle. This state of affairs was a bad sign of the genuineness of their faith.
Third, Paul warns them to not be deceived, and then describes those who will not enter God’s kingdom (neither fornicators, nor idolaters, nor adulterers, nor effeminate, nor homosexuals, 10 nor thieves, nor the covetous, nor drunkards, nor revilers, nor swindlers). Paul reminds the Corinthians that once they were practiced these things, but now exhorts them to leave it all behind, and embrace Christ in their life, in how they live.
I see Paul alluding to the topic of new birth which brings about new life, and includes the real battle of sin each believer contends with (Romans 6-7). Paul confronts the Corinthians wickedness with gospel truth and he calls them back to live in light of their identity. The real followers of Christ will eventually return to Christ, the hypocrites ultimately won’t.
So, it could be said that inept judgment is based on ignorance. That is, ignorance of our identity in Christ and our inheritance in Him inevitably results in a community that flounders rather than flourishes.
God give your church the grace to courageously, compassionately and swiftly deal with the strays within our own ranks as we entrust those outside the fold to You; the Just Judge who always does what is good beautiful and true.
 Peter Angeles, The Harper Collins Dictionary of Philosophy, pg.5, © 1992 by Peter A. Angeles