The Pew Forum on Religion & Public Life published a report today based on a survey of over 38,000 Muslims.

The survey revealed both unity and diversity in the world of Islam:
The world’s 1.6 billion Muslims are united in their belief in God and the Prophet Muhammad and are bound together by such religious practices as fasting during the holy month of Ramadan and almsgiving to assist people in need. But they have widely differing views about many other aspects of their faith, including how important religion is to their lives, who counts as a Muslim and what practices are acceptable in Islam, according to a worldwide survey by the Pew Research Center’s Forum on Religion & Public Life.
The survey, which involved more than 38,000 face-to-face interviews in over 80 languages, finds that in addition to the widespread conviction that there is only one God and that Muhammad is His Prophet, large percentages of Muslims around the world share other articles of faith, including belief in angels, heaven, hell and fate (or predestination). While there is broad agreement on the core tenets of Islam, however, Muslims across the 39 countries and territories surveyed differ significantly in their levels of religious commitment, openness to multiple interpretations of their faith and acceptance of various sects and movements.
You can read the full report here — The World’s Muslims: Unity and Diversity.