Islamic beliefs center around the concept of monotheism, which means believing in one God, referred to as Allah. Muslims, the followers of Islam, believe that Allah is merciful and compassionate. The core tenets of their faith are outlined in the Five Pillars of Islam, which include the declaration of faith, prayer, almsgiving, fasting during the month of Ramadan, and pilgrimage to Mecca. Muslims also believe in the prophets, with Muhammad being the final prophet. They regard the Quran as the holy book, believed to be the word of Allah as revealed to Muhammad. Additionally, they hold beliefs in angels, the Day of Judgment, and divine predestination.