The discussion of the comprehensiveness of religion, and its demonstration for a particular faith, is among the foundational issues in the study of religion. It plays a decisive role in various religion-related domains such as the derivation of legal rulings, the design of cultural, social, and political systems based on religion, and the development of religious human sciences. Establishing the comprehensiveness of a religion is contingent upon first demonstrating its possibility, which in turn depends on the existence of certain characteristics in realms such as the origin, the content, and the language of religion. This study, by presenting a novel framework for analyzing the comprehensiveness of religion, employs rational and analytical methods to examine these characteristics in the aforementioned realms. By applying this framework to Islam, the study concludes that the comprehensiveness of this religion is possible. This particular perspective on comprehensiveness will have implications and outcomes for "religious science", some of which are pointed out in the final section of the paper.