Belief in the Books
A Muslim should believe that Allah had sent down Books upon His Prophets and Messengers to clarify His Right and to call to it, as the Qur’aan says:
"Indeed We have sent Messengers with clear proofs, and revealed with them the Scripture and the Balance (Justice) that mankind may keep up justice." (Soorah 57:25)
"Mankind were one community and Allah sent Prophets with glad tidings and warnings, and with them He sent the Scripture in truth to judge between people in matters wherein they differed." (Soorah 2:2 13)
A Muslim should also believe in the Revealed Books that Allah named, such as the Torah, the Gospel, the Psalms, and the Qur’aan. The Glorious Qur’aan is the final and the best of all these Books. It confirms the Scriptures that came before it and is a witness over it, testifying the truth and falsifying the falsehood therein. All Muslims should follow its commands, shun its prohibitions and refer to its rulings to settle their differences. They should also follow the authentic Sunnah of the Prophet ! because Allah sent Muhammad ! to both the jinn and mankind and sent down the Noble Qur’aan to judge between them. He also made it a healing for the diseases, such as hypocrisy, ignorance and doubt, an exposition of everything, and a guidance and mercy for those who believe. The Qur’aan says:
"And this is a Book (i.e., the Qur’aan) which We have sent down as a blessing, so follow it and fear Allah, that you may receive mercy." (Soorah 6: 155)
"And We have sent down to you the Book (i.e., the Qur’aan) as an exposition of everything, a guidance, a mercy, and glad tidings to Muslims." (Soorah 16:89)
"Say (O Muhammad): 'O mankind! I am sent to you all as the Messenger of Allah, to Whom belongs the dominion of the heavens and the earth there is no God worthy of worship but He; it is He Who gives life and causes death. So believe in Allah and His Messenger, the Prophet who can neither read nor write (i.e., Muhammad !), who believes in Allah and His Words: follow him that you may be guided." (Soorah 7:158)
The Qur’aanic Verses to this effect are many.