It’s obligatory to believe that Allah, the one free from defects, sent down books to his Prophets and Messengers in order that they may explain and clarify his right and call to him. He the Most High, says:
“indeed, we have sent our Messengers with clear proofs and revealing within them the book and the balance (justice) that mankind may stand forth in justice” (57:25)
“mankind were one community and Allah sent prophets with glad tidings and warnings, and with them he sent the book in truth to judge between people in matters wherein they differed” (2:213)
We believe in the books mentioned by name, including the Torah, Injeel, Zaboor and the Quran.
The noble Quran is the last and best of all the books. It testifies to the truth within the old books, and it is obligatory for everyone to follow and judge by it along with the sunnah of the messenger of Allah (sallalahu alayhi wasallam). This is because Allah has made the Quran a cure for what is in the hearts, clarification for everything, and a guidance and mercy for the believers. Allah says:
“and we have sent down to you the book (Quran) as an exposition of everything and as a guidance and a mercy, and glad tiding are for those who have surrendered (to Allah as Muslims)” (16:89)