Hajji's religion is Islam, a monotheistic religion based on the teachings of the prophet Muhammad. It is one of the world's major religions, with over 1.8 billion adherents worldwide. Islam is centered around the belief in one God, Allah, and the teachings of the Quran, the holy book of Islam. The Five Pillars of Islam are the core beliefs and practices of the faith, which include belief in Allah, prayer, charity, fasting, and pilgrimage to Mecca.