Analysis of the presence of Imam among the Shiite thought and knowledge paradigms has been responsible for the essential role in the field of religious studies. A comprehensive, reasonable, and thoughtful analysis of various aspects of the issue of Imamate can bring about several normative and epistemological achievements. In the meantime, “the necessity of the presence of Imam from God’s viewpoint” as a rational necessity in the prevailing thought of Imamate school demands for a systematic and rational analysis.The current article explains and analyzes the issue of necessity of the existence of the Imam with a rational and logical approach with a focus on the ideas and works of Master Javadi Amoli in the form of various arguments and evidences. “Favor reasoning”, “the final reason” reasoning, “social order maintenance”, “the rule for possibility of the noblest”, “the rule for Oneness” are considered to be the most important rational arguments on the necessity of the existence of the Imam, each of which intends to provide a clear picture of the aspects of the issue of Imamate. Each of the five abovementioned arguments deals with the necessity of the existence of Imam from the Almighty God’s viewpoint in the caseworks and responds to the possible problems in some cases.