There is no Salvation Except through Faith in the Qur'an

"Say (O Muhammad ) "O people of the Scripture (Jews and Christians)! You have nothing (as regards guidance) till you act according to the Taurat (Torah), the Injeel (Gospel), and what has (now) been sent down to you from your Lord (the Qur'an)." Verily, that which has been sent down to you (Muhammad ) from your Lord increases in many of them their obstinate rebellion and disbelief. So be not sorrowful over the people who disbelieve." (Qur'an 5 : 68)

By 'establishing the Torah and the Gospel' is meant observing them honestly and making them the law of life.

It should be noted here that the Scriptures which comprise the Bible consist of two kinds of writings. One was composed by the Jewish and Christian authors themselves. The second consists of those portions which have been recorded as either the injunctions of Allah or as the utterances of Moses, Jesus and other Prophets. Such portions are those in which it has been categorically stated that Allah said so and so, or that a particular Prophet said so and so. If we were to exclude the portions belonging to the first category and carefully study those belonging to the second we would notice that their teachings are not perceptibly different from those of the Qur'an. It is true that the second category has not altogether escaped the tamperings of translators, scribes and exegetes, and the errors of oral transmitters. Nevertheless, one cannot help feeling that the teachings embodied in the second category call man to the same pure monotheism as the Qur'an, that they propound those very beliefs propounded by the Qur'an and that they direct man to the same way of life as that to which the Qur'an seeks to direct him. Hence, had the Jews and the Christians adhered to the teaching attributed in their Scriptures to Allah and the Prophets they would certainly have become a truth-loving and truth-oriented group of people and would have been able to see in the Qur'an that very light which illuminates the earlier divine Scriptures. There would then have been no question of their abandoning their religion in order to follow the Prophet (peace be on him). To follow him would have caused neither break nor discontinuity; they would simply have gone one stage further along the same road.

Instead of reflecting on this seriously and dispassionately, they were seized by a fit of intransigence which intensified their opposition.

Allah says: O Muhammad, say,

(O People of the Scripture! You have nothing...) meaning no real religion until you adhere to and implement the Tawrah and the Injil. That is, until you believe in all the Books that you have that Allah revealed to the Prophets. These Books command following Muhammad and believing in his prophecy, all the while adhering to his Law. Before, we explained Allah's statement,

(Verily, the revelation that has come to you from your Lord makes many of them increase in rebellion and disbelief.)

(So do not grieve for the people who disbelieve), Do not be sad or taken aback by their disbelief. Allah said next,

(Surely, those who believe) referring to Muslims,

(those who are the Jews) who were entrusted with the Tawrah,

(and the Sabians. ..) a sect from the Christians and Magians who did not follow any particular religion, as Mujahid stated. As for the Christians, they are known and were entrusted with the Injil. The meaning here is that if each of these groups believed in Allah and the Hereafter, which is the Day of Judgement and Reckoning, and performed good actions, which to be so, must conform to Muhammad's Law, after Muhammad was sent to all mankind and the Jinns. If any of these groups held these beliefs, then they shall have no fear of what will come or sadness regarding what they lost, nor will grief ever affect them. We discussed a similar Ayah before in Surat Al-Baqarah (2:62).