Embodying all the qualities of a perfect human being lie...
Embodying all the qualities of a perfect human being lie nurtures the spirits of his followers by means of his superabundant spirituality and lie shows them the way of advancing along God's path towards God obeying God's commands and turning away from all other than God. Only thus will the straight path remain open enabling everyone to embark on the road to felicity.
We will understand all of this better once we realize that there is no line of demarcation between this world and the hereafter and that regulations pertaining to man's bodily life cannot be separated from laws relating to his spiritual existence; a specific guardian has been chosen for both.
For this reason the pure and inerrant one chosen by God must gather in his hands the reins of the affairs of both this world and the hereafter and guard the general and universal interest of Islam against other peoples and nations. ( 144 ) Through the blessed existence of this true leader this representative of God upon earth the sole path that exists for attaining true happiness remain open before men.
With his spiritual richness and wisdom of conduct he guides them on the road at the end of which they will find in the presence of God all the pure and noble qualities for which they yearn. It is true that among the Twelve Imams it was only 'Ali b. Abi Talib who exercised rule and that for a limited period.
The other Imams never possessed governmental powers and they were not permitted to use the position of leadership that was rightfully theirs to strengthen the position of the Qur'an to expand the culture of Islam or to develop the identity of the ummah. But this was the fault of the people who failed to make it possible for them to assume power and as a result were deprived of the benefits that might have accrued to them from these unparalleled exemplars of mankind.
For in appointing the Imams God had established His proof before men; He had presented them with these righteous and exceptional men chosen ones whose existence was a source of benefit not only for all Muslims but for all of mankind. In addition to this it is important to remember that the beneficial effects of the existence of the Imams were not limited to their exercise of political power; they fulfilled their appointed mission in a variety of other ways.
The Imam was responsible for preserving the very truth of religion and for keeping God's religion unsullied by distortion and manipulation.