From the beginning of history, Iran have always been a religious country, and religion played pivotal role in it. Iran is a vast country in terms of area; therefore, only a powerful central power with religion as its basis can cause unity in society. Official religions in Iran includes Islam, Zoroastrianism, Christianity, Judaism and Mandaeism. Beside Mandaeism, which is not numbered in population, other religions have a representative in Iranian parliament.
Islam
Islam is the official religion of the country. Since the Arab’s conquest of Iran, little by little, people turned to Islam and its practice spread through the country. Quran is the holly book of Muslims, and the religion has two sects of Sunni and Shi’a (Shiite). The difference was made over the succession of Muhammad, the prophet of Islam. Sunni followers considered Abu Bakr, the advisor and right hand man of prophet to be his successor; however, the Shiites believed that after the death of the prophet, Ali (prophets cousin and son-in-law) should become the leader and director of Muslim. The dispute of the two group ended when Abu-Bakr finally came to power, but the bad blood remained for centuries. Since Ali and his defendants are blood related to the prophet, the followers of this sect are known to be the followers of the descendants of the prophet. About 10% of the Iranian population are Sunni Muslims and approximately 90% are Shia. The Shia has various sects itself, but most of Iranian are what is called 12-Imam Shiite that means the followers of the 12 descendant of the prophet. Shia became official religion of Iran from Safavid dynasty.
Zoroastrianism
The first official religion of Iran was Zoroastrianism, and the best and main source of knowing this religion is an ancient book known as Avesta. In the oldest section of Avesta that is attributed to Zoroaster himself, and is known as Gahan, Zoroaster teaches his followers that there is only one God, Ahura Mazda. He advises his followers to “Good Thoughts, Good Words, and Good Deeds” as the main principle of a good life. According to available inscriptions, Zoroastrian religion has been widespread in Iran since Achaemenid dynasty and realized as an official religion in Sassanid dynasty. Although, with the advent of Islam large number of Iranian converted to Islam but Zoroastrianism still has its followers in Iran.
Christianity
From the beginning of the first century B.C., Christianity spread in Iran and missionaries traveled to North West and West of the country. The Parthian rulers of Iran in that era believed in the freedom of religion, and Christians who were under prosecution in Rome found sanctuary in Iran. They built churches which many of them survived and is seen in Northwest of the country. The different sects of Christianity such as Catholic, Orthodox, Protestant, and Nestorianism have their own churches and hold their ceremonies in their churches. Each Christian who travel to Iran can hold religion ceremonies in these churches.
Mandaeism
The followers of Mandaeism are called Mandaeans. They are the followers of John the Baptist, and Mandaeism is considered a gnostic religion. Their holly script is the Ginza Rba or Ginza, a collection of history, theology, and prayers. The record of their presence in the country dates back to 2000 years ago. Baptizing in flowing water is one of the most important section of Mandaeism religion. Water has a specific and holly place among the adherents, and therefore, they live in places that is close to rivers. The followers of this religion are very secretive about their faith; they do not marry outside their tradition and never advertise their religion.
Judaism
The adherents of Moses, known widely as Jews, lived in Iran from 2700 years ago, and are among religion minorities of Iran. They pray in synagogue, and the tomb of Daniel in Susa and Esther and Mordechai Mausoleum in Hamadan are among the most important pilgrimage site of Jews in the country. They have specific school, cultural centers, as well as women organization that offers services to the followers of this religion and is forbidden for the rest to use. They also have specific shops for meats and food that is prepared according to Jewish tradition and law. These centers are especially found in cities of Isfahan, Hamadan and Khuzestan.