Muslim version of a primordial faith that has been revealed before through many prophets including Abraham, Ishmael, Isaac, Moses, and Jesus; that these previous messages and revelations have been partially changed or corrupted over time ("tahrif") and that the Qur'an is the final unaltered revelation from God (Final Testament). The religious practices of Muslims are enumerated in the Five Pillars of Islam: the declaration of faith ("shahadah"), daily prayers ("salat"), fasting during the month of Ramadan ("sawm"), almsgiving ("zakat"), and the pilgrimage to Mecca ("hajj") at least once in a lifetime. To become a Muslim and to convert to Islam, it
Muslim conquest of Persia were Sunni Muslims, though today Iran is known as a stronghold of the Shi'a Muslim faith, recognizing Islam as their religion and the prophet's son in law, Ali as an enduring symbol of justice. According to Amoretti in Cambridge History of Islam, the Arab conquerors brought with them a new religion and a new language, but they did not use force to spread it. While giving freedom of choice, however, the Arab conquerors designated privileges for those who converted. During the Rashidun Caliphate, the official language of Persia (including Mesopotamia) remained Middle Persian (Pahlavi), just as the official languages of