Why does God wait until the end of time to reward believers and judge the lost?
God reserves reward and judgment until the Lord comes, so nothing is judged before the proper time. Believers have not yet finished making impacts on people around them, and the lost have not reached the end of their time; therefore final reward and just recompense await the end.
In this Corinthian context, Paul is defending his apostleship and says no one can judge him except Jesus Christ, the Lord who sent him. Therefore, they are told to judge nothing before the time, until the Lord comes. Les explains that this is why believers will not receive their reward until the end of time, and the lost will not receive their just recompense until the end of their time. The reason given is that as believers go through this life, they are making impacts on people all around us, so the full outcome awaits the Lord’s coming.