John Chrysostom

"I charge thee therefore before God, and the Lord Jesus Christ, Who shall judge the quick and the dead." He either means the wicked and the just, or the departed and those that are still living; for many will be left alive. In the former Epistle he raised his fears, saying, "I give thee charge in the sight of God, Who quickeneth all things" (1 Tim. vi. 13): but here he sets before him what is more dreadful, "Who shall judge the quick and the dead," that is, Who shall call them to account "at His appearing and His kingdom." When shall He judge? at His appearing with glory, and in His kingdom. Either he says this to show that He will not come in the way that He now has come, or, "I call to witness His coming, and His kingdom." He calls Him to witness, showing that he had reminded Him of that appearing.