16:93
وَلَوْ شَآءَ ٱللَّهُ لَجَعَلَكُمْ أُمَّةً وَٰحِدَةً وَلَـٰكِن يُضِلُّ مَن يَشَآءُ وَيَهْدِى مَن يَشَآءُ ۚ وَلَتُسْـَٔلُنَّ عَمَّا كُنتُمْ تَعْمَلُونَ
walaw shāa l-lahu lajaʿalakum ummatan wāḥidatan walākin yuḍillu man yashāu wayahdī man yashāu walatus'alunna ʿammā kuntum taʿmalūna
If God so willed, He would have made you all one people, but He leaves to stray whoever He will and guides whoever He will. You will be questioned about your deeds.
And had Allâh willed, He could have made you (all) one nation, but He sends astray whom He wills and guides whom He wills. But you shall certainly be called to account for what you used to do.