Do not rejoice when your enemy falls, And do not let your heart be glad when he stumbles; lest the Lord see it, and it displease Him, and He turn away His wrath from him. (Proverbs 24:17-18)
We are to never rejoice in the misfortune or the sorrow of another. To do so may bring their reproach on ourselves. God has clearly said, "'Vengeance is Mine, I will repay,' says the Lord." Likewise the Lord asks, "'Do I have any pleasure at all that the wicked should die?' says the Lord God,‘and not that he should turn from his ways and live?’” Given that we did not get what we deserve with regard to judgment and punishment, surely we should hope that even our enemies would find repentance and God’s mercy. To take pleasure in the misfortune of our enemies is to rejoice in their eternal separation from God. If we truly understood what hell holds for those for whom it has been prepared, we would not want even our enemies to go there.