Yunus 19

وَمَا كَانَ ٱلنَّاسُ إِلَّآ أُمَّةً وَٰحِدَةً فَٱخْتَلَفُوا۟ وَلَوْلَا كَلِمَةٌ سَبَقَتْ مِن رَّبِّكَ لَقُضِىَ بَيْنَهُمْ فِيمَا فِيهِ يَخْتَلِفُونَ ﴿١٩﴾

Wama kana alnnasu illa ommatan wahidatan faikhtalafoo walawla kalimatun sabaqat min rabbika laqudiya baynahum feema feehi yakhtalifoona

Mankind were but one community (i.e. on one religion - Islamic Monotheism), then they differed (later), and had not it been for a Word that went forth before from your Lord, it would have been settled between them regarding what they differed. The Noble Quran