Legitimacy of a political system is the basis for the rulers’ authority and citizens’ obedience. During the history of mankind, it has been said that, the rulers have enjoyed divine power and divine right, divine legitimacy and religious legitimacy has been justified through the holy books and religious texts. The disagreement about the origin of legitimacy in Islam originates from epistemological and political elements. The Shiite consider divine authority in Imamat and see it as an inherent politico-religious principle whereas the Sunni consider divine authority as a result of consensus in Caliphate. The Shiite–Sunni disagreement about authority and obedience dates back to post-prophet era. Even the holders of human legitimacy try to present it as a divine blessing in order to ensure their survival. The final part of this article surveys the political thought of the Shiite during the time of Imam Zaman’s absence in four stages: from the time of the formation of religious identity of the Shiite to the Islamic republic of Iran.