And had God willed He would have made them one community in other words following one religion and that is Islam; but He admits whomever He will into His mercy and the evildoers the disbelievers have neither guardian nor helper to ward off the chastisement from them.
- 42:88
وَلَوْ شَاءَ اللَّهُ لَجَعَلَهُمْ أُمَّةً وَاحِدَةً وَلَٰكِنْ يُدْخِلُ مَنْ يَشَاءُ فِي رَحْمَتِهِ ۚ وَالظَّالِمُونَ مَا لَهُمْ مِنْ وَلِيٍّ وَلَا نَصِيرٍ
If God had pleased He would have made them one community of belief; but He admits whom He please to His grace; yet the sinners have neither friend nor helper.
- common.revelation-Meccan
- common.hizb : 193