Asking the reasons for the existence of governments is a question which proceeds the existence of governments logically. Without giving a proper answer to the question; and regarding its suitable space, we cannot find an appropriate convey to justify the existence of governments in various societies. In addition, regarding the space of market-oriented governing on the  economic theories and elaborating the areas to which the government can access and interfere in will depend on elaborating the reasons for the existence of governments. Preventing from market failure, government failure, and from general values failure are answers that western thinkers have given to these questions. They have tried to determine the limits of the government activities. In addition to deliberate the books and articles in this field, review these answers, and criticize them generally, we will try to assimilate the resulted views and unite them in one single approach. Then, the reasons of the existence of the government from the viewpoints of the Islamic sources will be explained and their differences with those of the western thinkers will be elaborated; differences can generally be called pursuing common expediences instead of common interests.