and He, exalted, says:

“O Messengers, eat of what is wholesome and act righteously, for I am indeed All-Knowing of what you do. This community of yours is one single community, and I am your Lord, so be mindful of Me. Yet they divided their affair among themselves into factions, each party delighted with what it possessed.” (al-Muʾminūn 23:51)

And—after relating the stories of the prophets—He said:

“Indeed, this community of yours is one single community, and I am your Lord, so worship Me. But they split their affair among themselves; all of them will return to Us.” (al-Anbiyāʾ 21:92)

And He, exalted, says:

“He has ordained for you in religion what He enjoined upon Noah, that which We have revealed to you, and what We enjoined upon Abraham, Moses, and Jesus: Establish the religion and do not break up into factions concerning it.” (ash-Shūrā 42:13)

And He, exalted, says:

“So set your face toward the religion, turning away from all that is false, in accord with the innate disposition with which Allah created mankind—there is no altering Allah’s creation. That is the upright religion, though most people do not know—turn to Him, be mindful of Him, establish prayer, and do not be among the polytheists, those who split up their religion and became sects, each party rejoicing in what it had.” (ar-Rūm 30:30)