[10] In Twelver Shi’ism, Muhammad is believed to have been succeeded by a line of twelve imams from his descent,[13] who also inherited his divine knowledge of religion.
[17] Indeed, temporal leadership only materialized for the first of the twelve imams, Ali ibn Abi Talib, who reigned from 661 CE until his assassination in 665.
[20] In addition to their exoteric function,[21] the twelve imams, by virtue of their divine knowledge, are regarded as the sole authoritative guides toward salvation,[22] as they initiated a small group of their followers into esoteric aspects of the religion.
[26] Their duty is essentially threefold: first, rule the community as Muhammad's rightful successors,[27] second, teach hidden aspects of the revelation and authoritatively interpret ambiguous verses of the Quran,[28] and third, guide men in their spiritual life.
[29] In this world, they are thought to be the cause for the creation, and the source of sustenance and divine blessings for creatures, thus maintaining all life on Earth.
[33] For instance, one rational argument in favor of imamate contends that mankind has a permanent need for a divinely-guided (infallible) leader and an authoritative teacher in religion,[34] one that would expound the divine law and correctly interpret the revelation.
[37] Providing this figure, called imam, is therefore incumbent upon God at any moment, as an obligatory grace (lutf wajib), for He acts in the best interest of His creation.
[38] Conversely, absence of such an imam would imply that God is both uncaring, for He has neglected His creation, and unjust, for He would punish men without providing them with right guidance.
[44] In Twelver doctrine, imamate is confined to certain descendants of the Islamic prophet Muhammad, from the marriage of his daughter Fatima to his cousin Ali ibn Abi Talib.
[45] Every imam is believed to have been designated by his predecessor through a divine mandate, going back successively to the announcement of Muhammad about Ali ibn Abi Talib at the Ghadir Khumm, shortly before the former died in 630.
[53] Divinely-sanctioned designation (nass) is often accompanied in Shia sources by inheritance of secret religious scrolls and prophet's weapons.
[55] Nass is regraded as a logical necessity in the Twelver doctrine, in which imams are thought to have been infallible, that is, immune from sin and error.
[72] It is thus said that imams knew the greatest name of God (ism Allah al-a’zam),[73] the past, the present, and the future.
As with the Islamic prophet Muhammad, the twelve imams are regarded as infallible in Twelver Shi'ism, that is, protected from sin and error through divine grace.
[76] Infallibility (isma) of imams, in their capacity as divinely-sanctioned leaders, is viewed as a logical necessity in Twelver Shi'ism lest the religion is corrupted,[77] or people are led astray.
[88] Yet the twelve imams are believed to have been equal in knowledge, although some of them, like Ali ibn Abi Talib, may have been superior to the rest in rank.
[90] At a mystical level, Muhammad, Fatima, and the twelve imams, collectively known as the fourteen infallibles, are said to have been created from a nobler substance than the clay from which prophets were made.
[97] In particular, as the divinely-sanctioned guide, imam is the highest proof (hujjat) of God on Earth and His evidence on the judgement day against those who deny or disobey Him.
[103] It is believed that the fourteen infallibles will intercede for the Muslim community in the hereafter,[104] through which their sins will be overlooked or they will reach a higher spiritual status.
[119] Not only absolute obedience to them is obligatory,[120] love for them is also mandated in the Quranic verse of the mawadda, according to Twelver (and some Sunni) exegetes.
[122] the above all-encompassing bond of spiritual loyalty that binds true followers to their imams is called walaya, transcending politics and self-interest.
[123] Walaya is the condition for the acceptance of all good deeds and salvation,[124] It is regraded as a pillar of the faith (iman),[125] and what elevates (true) Shias over the rest of Muslims, who have merley submitted to the exoteric Islam.
[41] Other Shia sources claim that Imams are expressed in Quran as: "the Supreme Sign" (al-Ayat al-Kobra) (79:20), "the August Symbol" (al-Mathal al-a'la) (16:60), "the Most Solid Handle" (al-Urwat al-Wuthqa) (2:256), (31:22).
Wilferd Madelung, regarding the blood ties which is found in Quran, states the superiority of Ali for his succession.
Regarding rejecting the Imamah-doctrine, Allamah Al-Hilli, a 14th century Shi'a Twelver Islamic scholar, writes: "Imamah is a universal grace (lutf ‘amm) while Nubuwwah (prophethood) is a special grace (lutf khass), it is possible that a specific period in time can be void of a living Nabi while the same is not true for the Imam.
[148] In the second and third century of Hijra, a Ma'sum (infallible) and divinely chosen leader of the religion was more focused than the political role of the Imams by the theologians.
[149] Although Imamiyah believed that most of the works on the early Islamic centuries argue that Shi'ism began as a political movement rather than a religious group.
[151] Dakake believes that the doctrine of Imamate was established in the time of Ja'far al-Sadiq, while Kohlberg states that the Twelver Shi'ism dates back not much before the beginning of the "Major_Occultation".
[citation needed] The Shi'a Twelver denomination of Islam consider it to be the highest level of responsibility given by God to a human.
[citation needed] Wali Allah Bab-e-Madina tul Ilm Asadullah Abu Turab Al-Karrar Al-Murtadha As-Siddiq Al-Wasi Al-Faruq Al-Sibt Sayyid al-Shabab Ahl al-Jannah As-Sayyid Al-Sibt Al-Wafi Al-Mubarak Zayn ul Abideen Sayyid al-Sajjadeen Dhu al-Thafenat Al-baqara Al-Shakir Al-Fadil At-Tahir al-Abd al-Salih Bab al-Hawa'ij Nafs Zakiyyah Ziynul Mujahidin Az-Zahid As-Sabir Ar-Razi Al-Wafi Al-Taqi Al-Naqi al-Mutawakkil Al-Samet Al-Zaki Al-Rafiq Al-Taqiy Al-Qa'im Al-Montazar Saheb al-Zaman Al-Gha'ib Al-Hojja Sahib al-Amr Sahib al-Haqq Baqiyat-Ullah