Surah Aal-e-Imran, Verse 103:
وَاعْتَصِمُوا بِحَبْلِ اللَّهِ جَمِيعًا وَلَا تَفَرَّقُوا وَاذْكُرُوا نِعْمَتَ اللَّهِ عَلَيْكُمْ إِذْ كُنتُمْ أَعْدَاءً فَأَلَّفَ بَيْنَ قُلُوبِكُمْ فَأَصْبَحْتُم بِنِعْمَتِهِ إِخْوَانًا وَكُنتُمْ عَلَىٰ شَفَا حُفْرَةٍ مِّنَ النَّارِ فَأَنقَذَكُم مِّنْهَا كَذَٰلِكَ يُبَيِّنُ اللَّهُ لَكُمْ آيَاتِهِ لَعَلَّكُمْ تَهْتَدُونَ

And hold fast, all of you together, to the Rope of Allah (i.e. this Quran), and be not divided among yourselves, and remember Allah's Favour on you, for you were enemies one to another but He joined your hearts together, so that, by His Grace, you became brethren (in Islamic Faith), and you were on the brink of a pit of Fire, and He saved you from it. Thus Allah makes His Ayat (proofs, evidences, verses, lessons, signs, revelations, etc.,) clear to you, that you may be guided.