'Judgment day' in the Bible

[the quality of] each person's work will become evident [i.e., for what is it made of]. For the [judgment] day will expose his workmanship. And it will be revealed by the fire [of judgment], which will test the quality of a person's workmanship [i.e., the faithfulness of his converts].

to turn such a person over to Satan for his body to be destroyed [Note: This probably refers to his removal from their fellowship. See verse 2], in order for his spirit to be saved in the day of the Lord [i.e., the judgment day]. [Note: This implies that his removal from their fellowship will have produced a genuine repentance before that time].

Or, do you not know that God's people will judge the world? [Note: Possibly this refers to Christians somehow assisting Christ on the judgment day]. And if the world is [to be] judged by you [at that time], are you not capable of judging small matters [now]?