Surah Hud — Ayah 118 (11:118)
وَلَوۡ شَآءَ رَبُّكَ لَجَعَلَ ٱلنَّاسَ أُمَّةٗ وَٰحِدَةٗۖ وَلَا يَزَالُونَ مُخۡتَلِفِينَ ١١٨
English translation (Saheeh International)
And if your Lord had willed, He could have made mankind one community; but they will not cease to differ,
Brief commentary
If your Lord, O Messenger, willed to make people one nation on the truth, He would have done so; but He did not will that, so they continue to differ with respect to it because of their following their desires and doing wrong.