Paul reminded the Corinthians that one day they would judge the world.
Or do you not know that the saints will judge the world? And if the world is to be judged by you, are you incompetent to try trivial cases? Do you not know that we are to judge angels? How much more, then, matters pertaining to this life! (1 Corinthians 6:2–3)
By asking “do you not know” twice he signals that he had taught them this before, which means that it wasn’t a Christian 500 level course. While this judging was a future gig, it had present implications. Why would they keep embarrassing themselves by bickering in front of unbelieving judges? There was something about their future responsibility that wasn’t disconnected from their present relationships. They should judge better now because they will judge later.
It also seems to be true that it works in the other direction: judging now makes for better judging later. In Revelation 20 John sees some who are sitting on thrones, and part of their job is to judge (verse 4). There are others who are raised to reign with Christ, which includes authority to judge, who had refused to take the mark of the beast, even as it cost them their lives. This is exactly the kind of judge you want. These judges couldn’t be bribed or bought or canceled even if killed. They held fast to the truth. Ability to distinguish between right and liars was not just a glorification supplement.
As Christians, our future is one of being judges. Some of that should be demonstrated in our contracts and communication with one another. And a lot of it should be demonstrated in our consecration to the Lord and our confession of sin. When it comes to sin we should be unbribable.
As living sacrifices we “discern what is the will of God, what is good and acceptable and perfect” (Romans 12:2). We abound in “all discernment, so that you may approve what is excellent” (Philippians 1:9-10). This faculty of judgment includes laying “aside every weight and the sin that clings so closely” (Hebrews 12:1). Recognizing the standard of God’s Word and applying it accurately to our own behavior is a just practice, and we are going to get lots of practice.