Why don't believers receive their reward until the end of time?
Believers do not receive their reward until the end of time because their lives continually influence others around them, and the full effect of those impacts must be allowed to play out. Judging must be deferred until the Lord comes, when He will rightly evaluate and reward. The lost likewise receive their just recompense at the end of their time.
Les explains that Paul tells the Corinthians to judge nothing before the time, until the Lord comes. The reason believers wait for reward until the end is that throughout life, believers are making impacts on people all around them. Those impacts and their consequences continue to unfold, so the full picture is not yet complete. Similarly, the lost will not receive their just recompense until the end of their time. Therefore, final evaluation and reward belong to the Lord at His coming, not to premature human judgment.