Many people at this level go back to their city of origin and become religious leaders. These men do not practice singing religious songs or participating in everyday life of the people. They usually run a mosque and lead people in the prayers five times a day. They answer peoples religious questions .They collect the religious taxation "Khoms, Zakat, and Hagh ol Imam" which has to be transferred to different Ayatollahs. They probably get a percentage, however I am not very familiar with this aspect of the deal, I just know that they push for the money and they have to send most of it higher up. They also develop a following of rich people, mostly the merchants who provide them with money one way or another.
Among some students who remain in the religious center become better-known, because they are better students, and have better command of several aspects of their education. They have to write certain books and must be able to teach the technical parts of the religious studies to others. The writing of several topics at the highest levels of Islamic religion is a must. At this point if they are good and have approval of several ayatollahs. They will get specific letters from those ayatollahs certifying that they have completed their studies and they are qualified to be called a "Mojtahed". A "Mojtahed is a clergyman who is educated and certified by other Ayatollahs to render his opinion on different religious matters.
Obviously it is very difficult to get to this point and there are only a few people in history who became a "Mojtahed" before the age of forty. It is at this point that they do gain momentum and referred to by their followers as an Ayatollah. Most of the Ayatollahs are older than sixty, and have very high IQs; currently there are about 80 ayatollahs in the world with the majority being in Iran.
The rest of the accomplishment of an ayatollah is more democratic. All Shiites are required to follow the teachings of an ayatollah. So if an ayatollah has a good name and heavy following then he automatically becomes a grand Ayatollah .He will write a book about how to conduct everyday life from a religious point of view.
A grand Ayatollah has a lot of power and if he writes a religious decree it has to be followed by his followers. With in the boundaries of Islam he has an open hand to order what he thinks is the best for Islam. Currently there are about 9 grand ayatollahs in the world.
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