Here is the fourth part of the Introduction from the book titled 250 Year Old Human by Ayatullah Khamenei.
Introduction [Part 4]
When I say Aa’ima (as), this means all the Aa’ima (as) from Amir al-Momineen (as) to Imam al-Askari (as). I have said many times that the life of the Aa’ima (as), which was spread across 250 years, needs to be recounted by us as if it is a life of one person. One person that is 250 years old; they are not separate from each other, ‘They are all one light’. Each of them who said something was in reality something which was said by the others too. Each of them carried out an action which was in reality an action of the others too. Just like a single person who has lived for 250 years. All the actions of the Aa’ima (as) in the stretch of these 250 years were the work of one person who had one objective, with one intention but different tactics were applied.
When the Aa’ima (as) felt that Islam had fallen into loneliness and that the Islamic Society had not been formed, they formed certain objectives as their principal objectives. One of them was the elucidation of the right picture of Islam. In the eyes of those that held power during the stretch of those long and lengthened years, Islam was something that was obtrusive. The Islam of the Prophet (pbuh), the Islam of the Qur’an, the Islam of Badr and Hunayn, the Islam that is against luxurious desires, the Islam that is against prejudice, the Islam which is a supporter of the weak and the Islam that is a crusher of the arrogant was of no use to those who wished to wear the cloak of Musa with their nature [being that] of the Pharaoh, [or] that of Ibrahim with their nature being that of Nimrod; [this was] not possible. They had no choice but to distort Islam, there was no possibility that they could have, all at once, taken away Islam from the hearts of the people, or the minds of the people, because the people were faithful hence they had no choice but to change and empty Islam of its spirit, its content and its nature.
If you remember, this is exactly what took place, and you witnessed, during the time of the previous regime [Pahlavi] in relation to the apparent aspects of Islam. The previous regime showed no opposition to Islamic demonstrations, however, with the meaning and spirit of Islam; of course [they showed opposition], with struggle (Jihad) in Islam; of course [they showed opposition], with the encouragement of good and discouragement of vices in Islam; of course [they showed opposition], with the expression of true Islam; of course [they showed opposition], however, against the apparent [version of] Islam, which would not even hurt their cows or sheep, they should no opposition. This state of affairs was also present during the rule of the Umayyad and Abbasid caliphates. To empty Islam from its spirit and realities, some of their workers had their income tied with their pens and some had their income tied with their tongues. They [the rulers] gave money and they [the workers] fabricated traditions, they [the rulers] gave money and they [the workers] created praises [for the rulers], they [the rulers] would give money and they [the workers] would make books for the rulers. [Someone has] said that when Suleiman ibn Abdullah left this world, we saw that the books of a big scholar, whose name I will not mention, being loaded on animals; on mules, and was being brought out of the safes of Suleiman ibn Abdullah. Meaning that this [the person who wrote the books], this great narrator, this well known scholar whose name is found in so many Islamic books today, used to write for Suleiman ibn Abdullah. Well, now books that are written for Suleiman ibn Abdullah, do you expect they will contain anything which might make Suleiman ibn Abdullah unhappy? Suleiman ibn Abdullah, that oppressed, drank alcohol, assembled with the unbelievers, suppressed the Muslims, held prejudice amongst the people and suppressed/put pressure on those in poverty, what kind of Islam would he like? This was the biggest pain for the Islamic society in the first century, this is what the Aa’ima (as) saw, they felt like the valuable inheritance of the Prophet (pbuh), meaning the Islamic rulings which have to remain for the rest of time and guide the people from all periods, was being exposed to distortion. [So] one of the very important objectives of the Aa’ima (as) was the correct elucidation/explanation of Islam [meaning] the true explanation of the Quran and exposition of distortions and distorters.
 Ayyun Akhbaar al-Ridha (as); Translation of Ghaffari/Mustafid V.2 p.417