Knowledge of the origin of faith is one of the most important and effective issue that should be taken into consideration when making a comparative study between two most popular and influential religions of the world i.e. Christianity and Islam. All teachings of Islam and Christianity have been directly or indirectly taken from their sources. In addition to the teachings of these two religions, knowledge of status of their sources is also of high importance. These sources are: the Bible, the Holy Quran and Sunnah.

The author of the present paper deals with Sunnah as interpreters of the Holy Quran in Islam and the Bible in Christianity. In the first part of this paper, the author presents an Islamic definition of Sunnah from two perspectives: Shia and Sunni. In the second part he makes a comparison between Islamic and Christian view of Sunnah along with a criticism of Christian approach to the functions of Sunnah.

Key Words: The Holy Quran, the Bible, Sunnah, Sayings and Deeds of the Holy Prophet, Interpretation, New Development, the Holy Ancestors, Authoritarian Reform Movement, Ante-Fundamental Reform Movement.

* * * * *