Islam and Sikhism Moses, Jesus and Mohammed in other religions. Islam believes that before Muhammad there were many messengers of God, Muhammad was the last messenger, and Quran was the last revelation to the last prophet. The Five Pillars of Islam are duties incumbent on every Muslim. These duties are Shahada (testimony that "There is no god but God and Muhammad is the messenger of God"), Salat (prayers), Zakat (Giving of Alms), Sawm (Fasting during Ramadan) and Hajj (pilgrimage to Mecca). These five practices are essential to Sunni Islam; Shi'a Muslims subscribe to eight ritual practices which substantially overlap with the five Pillars.
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