Souls are troops collected together and those who familiarised with each other (in the heaven from where these come) would have affinity, with one another (in the world) and those amongst them who opposed each other (in the Heaven) would also be divergent (in the world).  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ الأَرْوَاحُ جُنُودٌ مُجَنَّدَةٌ فَمَا تَعَارَفَ مِنْهَا ائْتَلَفَ وَمَا تَنَاكَرَ مِنْهَا اخْتَلَفَ  

People are like mines of gold and silver; those who were excellent in Jahiliya (during the days of ignorance) are excellent In Islam, when they have, an understanding, and the souls are troops collected together and those who had a mutual familiarity amongst themselves in the store of prenatal existence would have affinity amongst them, (in this world also) and those who opposed one of them, would be at variance with one another.  

النَّاسُ مَعَادِنُ كَمَعَادِنِ الْفِضَّةِ وَالذَّهَبِ خِيَارُهُمْ فِي الْجَاهِلِيَّةِ خِيَارُهُمْ فِي الإِسْلاَمِ إِذَا فَقُهُوا وَالأَرْوَاحُ جُنُودٌ مُجَنَّدَةٌ فَمَا تَعَارَفَ مِنْهَا ائْتَلَفَ وَمَا تَنَاكَرَ مِنْهَا اخْتَلَفَ