Had Allah willed, He could have easily made you one community, but He leaves to stray whoever He wills and guides whoever He wills. And you will certainly be questioned about what you used to do.

وَلَوْ شَاءَ اللَّهُ لَجَعَلَكُمْ أُمَّةً وَاحِدَةً وَلَٰكِن يُضِلُّ مَن يَشَاءُ وَيَهْدِي مَن يَشَاءُ وَلَتُسْأَلُنَّ عَمَّا كُنتُمْ تَعْمَلُونَ

—Qur'an 16:93