Quran 49:13 — The Walls (Al-Hujurat)

O people, we created you from the same male and female, and rendered you distinct peoples and tribes, that you may recognize one another. The best among you in the sight of GOD is the most righteous. GOD is Omniscient, Cognizant.

[49:12] O you who believe, you shall avoid any suspicion, for even a little bit of suspicion is sinful. You shall not spy on one another, nor shall you backbite one another; this is as abominable as eating the flesh of your dead brother. You certainly abhor this. You shall observe GOD. GOD is Redeemer, Most Merciful.

[49:14] The Arabs said, "We are Mu'mens (believers)." Say, "You have not believed; what you should say is, 'We are Muslims (submitters),' until belief is established in your hearts." If you obey GOD and His messenger, He will not put any of your works to waste. GOD is Forgiver, Most Merciful.