The above map gives a basic overview of the areas where the six main world religions are dominant. The six world faiths are though spread throughout the world.
Originating in Arabia, Islam has spread throughout the world and there is an estimated 1.1 billion Muslims in the world (see the Rise of Islam).
It is the fastest growing religion in America (US News and world report 1990). There are approximately 1,000,000 – 1,500,000 active Muslims in the UK. Historically Islam has been more dominant in Asia and Africa and countries with a high population of Muslims are Indonesia, Pakistan and Saudi Arabia.