Indeed, the religion in the sight of Allah is Islam. And those who were given the Scripture did not differ except after knowledge had come to them – out of jealous animosity between themselves. And whoever disbelieves in the verses of Allah , then indeed, Allah is swift in [taking] account.
Surat ‘Ali `Imran (Family of Imran) 3:19

And whoever desires other than Islam as religion – never will it be accepted from him, and he, in the Hereafter, will be among the losers.
Surat ‘Ali `Imran (Family of Imran) 3:85

O People of the Scripture, why do you argue about Abraham while the Torah and the Gospel were not revealed until after him? Then will you not reason? Here you are – those who have argued about that of which you have [some] knowledge, but why do you argue about that of which you have no knowledge? And Allah knows, while you know not. Abraham was neither a Jew nor a Christian, but he was one inclining toward truth, a Muslim [submitting to Allah ]. And he was not of the polytheists.
Surat ‘Ali `Imran (Family of Imran)3:65-67

But when Jesus felt [persistence in] disbelief from them, he said, “Who are my supporters for [the cause of] Allah ?” The disciples said,” We are supporters for Allah . We have believed in Allah and testify that we are Muslims [submitting to Him].
Surat ‘Ali `Imran (Family of Imran)3:52

He has ordained for you of religion what He enjoined upon Noah and that which We have revealed to you, [O Muhammad], and what We enjoined upon Abraham and Moses and Jesus – to establish the religion and not be divided therein. Difficult for those who associate others with Allah is that to which you invite them. Allah chooses for Himself whom He wills and guides to Himself whoever turns back [to Him].
Surat Ash-Shuraá (The Consultation) 42:13