Allah the Exalted and Most Honored said,

[وَاتَّقُواْ اللَّهَ]

(And have Taqwa of Allah), that is, regarding what He has commanded you and forbidden for you. Fear Him and beware of Him,

[إِنَّ اللَّهَ تَوَّابٌ رَّحِيمٌ]

(Verily, Allah is the One Who forgives and accepts repentance, Most Merciful.) He forgives those who repent to Him, is merciful with those who go back to Him and trust in Him. The majority of scholars have stated that repentance for committing the sin of backbiting is that one refrains from backbiting intending not to repeat it again. There is a difference of opinion if whether feeling remorse is required in this case, and also if one should apologize to those who he has backbitten. Some scholars stated that it is not necessary for one to ask those whom he has backbitten to forgive him, because if they knew what was said about them, they could be hurt more than if they were not told about it. It is better, they said, that one should praise those whom he has backbitten in audiences in which he has committed the act. It is also better if one defends the injured party against any further backbiting, as much as one can, as recompense for his earlier backbiting.

[يأَيُّهَا النَّاسُ إِنَّا خَلَقْنَـكُم مِّن ذَكَرٍ وَأُنْثَى وَجَعَلْنَـكُمْ شُعُوباً وَقَبَآئِلَ لِتَعَـرَفُواْ إِنَّ أَكْرَمَكُمْ عَندَ اللَّهِ أَتْقَـكُمْ إِنَّ اللَّهَ عَلِيمٌ خَبِيرٌ ]

(13. O mankind! We have created you from a male and a female, and made you into nations and tribes that you may know one another. Verily, the most honorable of you with Allah is that (believer) who has At-Taqwa. Verily, Allah is All-Knowing, All-Aware.)