8:25

And fear the Fitnah (affliction and trial, etc.) which affects not in particular (only) those of you who do wrong (but it may afflict all the good and the bad people), and know that Allah is Severe in punishment.
Meaning:-
Fitnah: ( Al-Fitnah is worse than killing.) Spreading Mischief, trying to force the Muslims to revert from their religion and re-embrace Kufr after they had believed, is worse with Allah than killing.
Afflict: (of a problem or illness) cause pain or suffering to; affect or trouble.