(An-Nahl) 16 : 126
وَإِنْ عَاقَبْتُمْ فَعَاقِبُوا بِمِثْلِ مَا عُوقِبْتُمْ بِهِ ۖ وَلَئِنْ صَبَرْتُمْ لَهُوَ خَيْرٌ لِلصَّابِرِينَ
And if you are retaliating, retaliate in an equivalent of that with which you were harmed, but if you are patient, it is better for those who are patient.
To have peace and harmony of mankind and to annihilate mischievous activities, Lord’s rules and regulations which is Adhikr should be implemented among mankind as explained in verses 2: 178-179. It is possible when there is a group of believers who testify Adhikr. See explanation 2: 155; 5: 44-50 and 9: 123.