وَلَو شاءَ اللَّهُ لَجَعَلَهُم أُمَّةً واحِدَةً وَلـٰكِن يُدخِلُ مَن يَشاءُ في رَحمَتِهِ ۚ وَالظّالِمونَ ما لَهُم مِن وَلِيٍّ وَلا نَصيرٍ

Had God willed, He could’ve made them one community, but He admits into His mercy whom He wills. The wrongdoers have no protector or helper.