The Imam as Mentioned in Traditions
There are many traditions, which define the Imam and Imamate, one of which we mention here. The eighth infallible Imam of the Shiah, Imam Riza (`a) stated,
Imamate is the position of the prophets (s) and the heritage of their successors. Imamate is caliphate of Allah and His Messenger and the position of Amiral Mu’minin, Imam Ali (`a), (Imam) Hassan (`a), and (Imam) Hossein (`a). Imamate is governing Muslims’ religion and system, worldly prosperity and honor. Imamate is the basis of blossoming tree of Islam and its young branches. The Imam manages well the issues related to salat (regular prayers), sawm (fasting), zakat (statutory Islamic levy), hajj (pilgrimage of the ka’bah), jihad, developing government properties, sadaqat (alms), execution of commandments and hudud (Islamic punishment defined for specific sins), and guarding the boundaries.
The Imam is Allah’s trusted servant among the people, His hujjat (sign) for the servants, His caliph in lands, inviter to Allah’s religion, and protector of Allah’s sanctuary. The Imam is infallible and away from sins and vices. He is abound with knowledge and patience, the pillar of religion, honor of Muslims, and the cause of anger and perish of the infidel and the heterodox. The Imam is a unique personality in his own age; no one can replace him and no scholar reaches his scientific stance. The Imam’s virtues and goodness are not obtainable; rather he has reached such a position by Allah’s Mercy.
 Usul Kafi, Vol 1, p. 200.