"if you do bad, it will be against your souls" (Sura AL-ISRA, Verse 7), whoever you ail, it gets back to you. The system of universe is in a way that the afflicted person will not have the pain forever and it comes back to you. Some people say: " why are we in trouble all the time?" they should think and find the reason for their trouble, it can be found, they just need to think.
source : erfan.ir