threat and does not allow Salafis to build mosques in Tehran or other large cities due to the fear that these mosques could be infiltrated by extremists. It is reported that members of religious minority groups, especially Sunni Muslims who supported rebels during the Syrian Civil War, are increasingly persecuted by authorities. The government imprisons, harasses and discriminates people because of their religious beliefs. Sufism The Safaviya sufi order, originates during the Safavid dynasty 700 AD. A later order in Persia is the Chishti. The Nimatullahi are the largest Shi'i Sufi order active throughout Iran and there is the Naqshbandi, a Sunni order active mostly in the Kurdish regions of Iran. The Oveyssi-Shahmaghsoudi order is the largest Iranian Sufi order which currently operates outside of Iran. Famous Sufis include al-Farabi, al-Ghazali, Rumi, and Hafiz. Rumi's two major works, Diwan-e Shams and Masnavi, are considered by some to be the greatest works of Sufi mysticism and literature. Since the 1979 Revolution, Sufi practices have been repressed by the Islamic Republic, forcing some Sufi leaders into exile. While no official statistics are available for Sufi groups, there are reports that estimate their population between two and five million (between 3–7% of the population). Christianity Christianity has a long history in Iran, dating back to the very early years of the faith. And Iran's culture is thought to have affected Christianity by introducing the concept of the Devil to it. There are some very old churches in Iran – perhaps the oldest and largest is the Monastery of Saint Thaddeus, which is also called the Ghara Kelissa (the Black Monastery), south of Maku. By far the largest group of Christians in Iran are Armenians under the Armenian Apostolic Church which has between 110,000, 250,000, and 300,000 adherents. There are many hundreds of Christian churches in Iran, with at least 600 being active serving the nation's Christian population. As of early 2015, the Armenian church is organized under Archbishop Sepuh Sargsyan, who succeeded Archbishop Manukian, who was the Armenian Apostolic Archbishop since at least the 1980s. Unofficial estimates for the Assyrian Christian population range between 20,000, and 70,000. Christian groups outside the country estimate the size of the Protestant Christian community to be fewer than 10,000, although many may practice in secret. There are approximately 20,000 Christians Iranian citizens abroad who left after the 1979 revolution. Christianity has always been a minority religion, overshadowed