List of religious populations

There are twelve classical world religions—those religions most often included in history of world religion surveys and studied in world religions classes: Baha’i, Buddhism, Christianity, Confucianism, Hinduism, Islam, Jainism, Judaism, Shinto, Sikhism, Taoism, and Zoroastrianism. Here are overviews of ten of these classical religions.

2. Islam – 1.8 billion followers

Islam  is a monotheistic, Abrahamic religion articulated by the Quran, a religious text considered by its adherents to be the verbatim word of God, and, for the vast majority of adherents, by the teachings and normative example  of Muhammad (c. 570–8 June 632 CE), considered by most of them to be the last prophet of God. An adherent of Islam is called a Muslim. Muslims believe that God is one and incomparable and that the purpose of existence is to worship God. Most Muslims are of two denominations: Sunni (75–85%) or Shia (15–20%)