Contemplating and discussing the functions of religion is one of the crucial problems in an Islamic society. In this regard, defending and articulating the epistemological functions of Islam proves both vital and challenging. Ayatollah Javadi Amoli, granting the perfect nature of Islam as a comprehensive system of faith in meeting the material and spiritual needs of humans, highlights such a need. He offers precise accounts of religion, reason, and knowledge, articulates various aspects of reason, and identifies the borderlines. He goes on to highlight the limitations of reason and distinctions between heavenly revelation and textual evidence and accounts for the functions of religion in providing the foundations and some data of science. By laying emphasis on the status of human beings as a subject in the epistemological processes like secular knowledge and authenticity of Islamic knowledge, Ayatollah Amoli examines the roots of western empirical traditions of secularizing human thought. Conceding the originality of knowledge in Islam, the solutions for the development of Islamic knowledge are offered. To this latter end, the changes in views and attitudes gain importance where naturalistic and secular philosophies need to be deemphasized at the cost of adopting a religious and particularly Islamic worldview that can ensure islamicizing knowledge. Eventually, the divine origin and revelation-based source prescribes philosophy as an advantage since it is deemed a facilitating tool for achieving such goals.