Our Scripture reading today is Proverbs 24:17-18.
Verse 17, "Rejoice not when thine enemy falleth, and let not thine heart be glad when he stumbleth:"
An example of this proverb being applied in the Bible is David. At two different times his father in law (King Saul) and son (Absalom) were trying to kill him. Neither one were successful and each time David did not glory in their defeat and ultimately their death. In fact, he mourned the death of both of his enemies. 2 Samuel 1:11-12, "Then David took hold on his clothes, and rent them; and likewise all the men that were with him: And they mourned, and wept, and fasted until even, for Saul..." 2 Samuel 19:1, "And it was told Joab, Behold, the king weepeth and mourneth for Absalom."
Whenever someone falls, we should be praying for them to repent and turn to God or back to God. The heart of God is for people to be saved and not go to the Lake of Fire. If anyone should be rejoicing in the punishment of the wicked, it should be God, and yet He is not willing for anyone to perish. Our heart should be one of compassion and restoration. I am sure it how we would want to be treated should we fall. Galatians 6:1, "Brethren, if a man be overtaken in a fault, ye which are spiritual, restore such an one in the spirit of meekness; considering thyself, lest thou also be tempted."