Islam is a monotheistic religion articulated by the Qur'an. Muslims believe in one God and that the purpose of existence is to love and serve God. The word "Islam" means "submission to God" in Arabic. The religion was founded by the prophet Muhammad in the 7th century to unite the Arab people, but it spread worldwide with Arabs originally making up 15-20% of adherents. The five main principles of Islam are the shahadah, prayer, fasting, charity, and the hajj pilgrimage.