The predominant religion in Armenia is Christianity. Christian communities have been established in Armenia since 40 AD by two of Jesus' twelve apostles – Thaddeus and Bartholomew – who preached Christianity in Armenia. Because of these two founding apostles, the official name of the Armenian Church is Armenian Apostolic Church.
Christianity has been declared as state religion in 301, when Armenia became the first to adopt Christianity as its official state religion. Conversion of Armenia connected with name of St. Gregory Illuminator (Surb Grigor Lusavorich in Armenian). Because of St. Gregory, Armenian Church is also referred to as the Gregorian Church, but “Apostolic” is more preferable.
The Christianization of Armenia determined the entire future course of Armenia's history. As a national church, it has played a vital role in maintaining Armenian culture, through the preservation and expansion of written traditions and as a cultural focus for Armenians scattered around the world. In the long periods when Armenians did not have a state of their own, the church was both a political and a spiritual leader, and religion was at the center of the Armenian national self-image.
The Supreme Spiritual and Administrative leader of the Armenian Church is His Holiness Garegin II, Supreme Patriarch and Catholicos of All Armenians, who is the worldwide spiritual leader of the Nation, for Armenians both in Armenia and dispersed throughout the world.
The spiritual and administrative center of the Armenian Church is the Holy city of Echmiadzin, west of Yerevan .
The modern Republic of Armenia is constitutionally a secular state, although the Christian faith plays a major role in the history and identification of the Armenian people. About 94 percent of the population of Armenia belongs to the Armenian Apostolic Church . Other religious communities, such as a Catholic, Evangelical, Orthodox, Yezidi, Judaic and Muslim also exist in Armenia .