(Pro 24:17 KJV) Rejoice not when thine enemy falleth, and let not thine heart be glad when he stumbleth:
This reminds me of the verse in I Corinthians13:6 which says we are not to rejoice in unrighteousness. Included in that idea is that we are not to enjoy the suffering of our enemies. We are to want the best for them and allow God to be the one who directs their path. He will bring them to repentance much better than we can. This is another difference between the teaching of the God of the Bible (Vengeance is mine, saith the Lord) and the perversion of the Koran. The Koran demands that the believer seek vengeance.
This is hard to apply. War is not condemned. Justice is demanded. We are supposed to see these activities through and not “rejoice” (8055) as the guilty “falleth" (5307). So much of what we experience is keyed to our attitudes in combination with our actions.