He alone in explaining the meaning of the Imamate, refers to the focus of his concern and his concentration in his conception of its reality, which is what convinced us of what he explains about the political role he was practically playing, as we have mentioned. As for the obligation of the Imamate: The Mahdi, like all Muslims of various sects, believed that the establishment of an Imam in the nation is an obligation for Muslims to believe in him and adhere to him in their conduct, which is what he meant by his saying: "Believing in it is religion, acting upon it is religion, and adhering to it is religion." The Imamate was obligatory because it is "the pillar and column of religion," and this means that religion, in its establishment among people, absolutely, at all times, and in the control of its rulings over creation, depends on an Imam who upholds its principles and works to implement them. He said in another place: "The truth cannot be established in this world except by the obligation to believe in the Imamate in every age until the Hour comes." The Mahdi did not explicitly state whether the obligation of the Imamate falls under the category of secondary rulings related to the actions of the accountable, as is the opinion of the Ash'aris and other sects besides the Shiites, or if it falls under the category of fundamental principles of religion and beliefs, as is the opinion of the Shiites, who believe that "the Imamate is one of the principles of religion, and faith is not complete except by believing in it. It is not permissible to follow fathers, family, or educators in it, no matter how great and esteemed they are, but rather one must look into it, just as one must look into monotheism and prophethood." However, we find him elevating the status of the Imamate and magnifying its importance, which makes us lean towards considering the Imamate as one of the principles of religion, like the Shiites. Some of those who held the opinion that the Imamate is permissible were the Najdat sect of the Kharijites, Abu Bakr al-Asamm and Hisham al-Futi from the Mu'tazilah. See al-Maqalat by al-Ash'ari, Usul al-Din by al-Baghdadi, al-Imamah by Ibn Tumart, and the same source. See also al-Amidi, Ghayat al-Muram fi 'Ilm al-Kalam, al-Aiji, al-Mawaqif and its commentary by al-Jurjani, and the two previous sources. Muhammad Reza al-Muzaffar, 'Aqa'id al-Imamiyyah.