Christianity has a long history in Iran, dating back to the early years of the faith. It has been practiced in Iran longer than the state religion, Islam. There are at least 600 churches for 300,000 - 370,000 Christians in Iran. The main churches in Iran are the Armenian Apostolic Church, the Assyrian Church of the East, the Chaldean Catholic Church of Iran, the Roman Catholic Church of Iran, and a number of Protestant churches as well. The majority of Christians are ethnic Armenians concentrated in Tehran and Isfahan. The actual number of Christian citizens in Iran is much higher than what is officially reported, as many Christians, particularly Assyrians, do not have Iranian citizenship and are not included in census data. Some sources say there are as many as 500,000 Christians in Iran.
The constitution gives the Zoroastrian, Jewish, and Christian communities protection to worship freely and to form religious societies, although any proselytizing by them is strictly prohibited. Five seats in the parliament are reserved for these groups (two for Armenian Christians and one each for Assyrian Christians, Jews, and Zoroastrians). Nevertheless, the government of Iran discriminates against its citizens on the basis of religion or belief, as all laws and regulations are based on unique Shi’a Islamic criteria.
Since the 1979 revolution, many members of minority religious communities have fled in fear of persecution. Although Christians are allowed to practice their faith, they face arduous government regulations and harassment including the monitoring of all Christian religious practice. All Christians who attend Church are required to register with the authorities, who reportedly forbid Muslim converts to Christianity from entering Armenian or Assyrian churches.