The Quran

Preface

وَما تَفَرَّقوا إِلّا مِن بَعدِ ما جاءَهُمُ العِلمُ بَغيًا بَينَهُم ۚ وَلَولا كَلِمَةٌ سَبَقَت مِن رَبِّكَ إِلىٰ أَجَلٍ مُسَمًّى لَقُضِيَ بَينَهُم ۚ وَإِنَّ الَّذينَ أورِثُوا الكِتابَ مِن بَعدِهِم لَفي شَكٍّ مِنهُ مُريبٍ

Yusuf Ali

And they became divided¹ only after Knowledge reached them,- through selfish envy as between themselves. Had it not been for a Word that went forth before² from thy Lord, (tending) to a Term appointed, the matter would have been settled between them: But truly those who have inherited the Book after them are in suspicious (disquieting)³ doubt concerning it.

Cf. 2:213. If you reject Truth after it has reached you, it can only be through selfish contumacy or envy.
Cf. 10:19, and n. 1407. God’s decree has allowed a certain Term during which a sinner has the chance of repentance and forgiveness. Were it not so, sin would be punished at once, and the matter would be decided straightaway. So also, when people reject Truth from selfish or contumacious motives, they get rope: perchance they may repent.
Cf. 14:9 and n. 1884. “Those who have inherited the Book” are the People of the Book, of the ages since the Book or Revelation came to them. Referring to the Jews and Christians contemporary with our Prophet, how true it is that they were broken up into hostile sects which hated and persecuted each other! Islam came to unite them, and it did. For the present phases of Christianity and Judaism are of later growth.