Islam has no “clergy” in the Christian sense
Islam is a religion that recognizes no authoritative source of doctrinal interpretation like the Pope.
The lack of an authoritative source of doctrinal interpretation means that Islam lacks a hierarchical structure like the Catholic Church and (theoretically) anyone can interpret the Quran and other religious scriptures any way they like.
This makes Islam more egalitarian and democratic in some ways but also makes it easier for Muslim extremists to gain influence and promulgate their views.
It is important to add that there being no accepted translation of the Arabic text of the Quran in any language, only the doctrinal interpretation of the Arabic text has any weight.
Muslims believe in direct communion with God and technically human intermediaries are not necessary for followers to have a relationship with God. Consequently there are no priests, popes, holy men, or saints in Islam.
Every Muslim has equal access to God and any Muslim of good character can be the leader of prayers at a masjid (mosque).
There is no concept of a “church” and no sacraments. Islam has rigorously excluded from its religious leadership any of the spiritual functions and prerogatives of priesthood.
The basis of some of Islam’s structures is rooted in Bedouin traditions of blood kinship, egalitarianism, and surrendering to strong authority (Allah in the case of Islam).
Islamic Community, Imam, and Sheikhs
Local Islamic communities form part of the umma– the world-wide community of Muslims which is more like a club than an organized church.
Each community should try to resolve their own problems by working together and they may well be involved in a number of community and charitable activities.
The local Islamic community is supposed to act as one, like a compact wall whose bricks support each other.
An imam is simply a teacher, a learned person or a person who leads the prayer.
Every masjid has an imam and an assistant imam that takes the place of the imam if he is sick or out of town, or “assists” if the imam stumbles or forgets a verse when reciting.
Imams or khatibs have traditionally led prayers and given sermons, much like a preacher in a Christian church.
Some imams are self-appointed and have little formal religious training, although this is changing.
Sheikh/Sheikha means teacher. It is the name given to a man/woman admired for his/her piety and knowledge.
Sheikhs and Sheikhas are sometimes preachers.
Clerics, Mullahs, Qadis, and Muftis
“Mullah” is an honorific word for a learned person who acts as a teacher and judge and who expounds Muslim law.
He is regarded more like a high-ranking professor of the religion rather than a priest.
A person generally needs to finish Quranic School to obtain the title of mullah.
“Ulama” refers to a class of mullah or religious scholars that are trained in theology and are respected interpreters of the Quran.
Influential in conservative and rural communities, many ulama can trace their lineage back to the Prophet or members of his family or his early followers.
In the past, they often formed the urban elite. They and their children were educated in the most prestigious madrasahs (Muslim schools). Ulama is the plural of alim (“scholar”), and ‘ilm is knowledge.
A Muslim judge is known as qadi. A mufti is an Islamic legal expert.
They began as assistants to judges; now many are high ranking legal experts and are allowed to issue fatwas – Islamic rulings – which in a non-Muslim country are recommendations only.