The Authority of the Qur'an over Previous Books

The Qur'an is a book that preserves, controls and testifies the basic provisions of other books, the principles of morality and faith. The fact that the Qur'an is referred to as "al-Muhaymin" (Ma'idah, 5/48)  expresses this fact. The Qur'an contains the teachings of all the divine books before it. In this way, it protects the parts of other books that need to believed from extinction. 

The accuracy and authenticity of the Torah and Gospel verses can be evaluated by taking the Qur'an as a benchmark. Those that pass the approval of the Qur'an are true, and those that do not are false and superstitious. When there is a contradiction between the information in the previous books and the Qur'an, the information in the Qur'an is respected. Because, although there are many human interventions, differences and contradictions in other books, the Qur'an has been protected from human intervention (Hijr, 15/9) and has not been subjected to any changes or falsifications since its revelation. For example, the Torah and the Psalms were lost over time and were rewritten at various times by Jewish clergymen. The Gospels were written long after the passing of Prophet Isa. The Qur'an, on the other hand, was dictated by the Prophet Muhammad (saw) himself during His time, and collected and made into a book shortly after His passing, and has survived both by memorization and writing. 

The concept of "Muhaymin" means that the Qur'an will be taken as a cornerstone in the evaluation of previous books. For this reason, it is not permissible for Muslims to act according to the provisions in other books that are not approved by the Qur'an or contradicts with it.

Throughout history, there has been a maturement in religion. Therefore, the Qur'an is the most perfect and comprehensive of the books. There are clear, fixed, continuous, unchanging principles (minhaj) of religion, such as faith in Allah (swt), the prophet and the Hereafter, and details (shir'a) that can change according to time, place and circumstances. As the last and most comprehensive book, the Qur'an contains the universal truths of the Torah and the Gospel, but has replaced the provisions that need to be changed with the appropriate ones. For this reason, after the revelation of the Qur'an to all people, Jews and Christians must believe in it.