The necessity of guidance and discussion of prophecy and the imamate rule

Shiite theologians have emphasized that the 'Rule of God's Favour' can explain the need to install the necessity of prophets and their successor Imam's mission. However, thanks to the rule based on the necessity of guidance, which relies on an Ayah in Holy Quran meaning 'the leading is upon them' and the rational arguments bearing the necessity of conducting the verse deserves more attention in making the case. This rule can range Prophethood and Imamate and cover broader relevant issues. Attention to this rule can be helpful in determining the shape and method of guidance. In this article, the basis and the principles of this rule are explored and provisions of the rule are explained. Then, based on a new understanding of the rules, its impact on the principles of the Imamate and Mahdism are mentioned. The main result of this article is updating the approach to the claims made on the Imamate guidance position and claims that are expressed in the signs of Presence.