Islam is a system of faith.
Islam . الإسلام , [ alʔisˈlaːm ] ) is an Abrahamic monotheistic religion which professes that there is only one and incomparable God ( Allah ) and that Muhammad is the last messenger of God . It is the world 's second-largest religion and the fastest-growing major religion in the world , with over 1.8 billion followers or 24.1 % of the global population , known as Muslims . Muslims believe that Islam is the complete and universal version of a primordial faith that was revealed many times before through prophets including Adam , Abraham , Moses , and Jesus . Religion . Different religions may or may not contain various elements ranging from the `` divine '' , `` sacred things '' , `` faith '' , a `` supernatural being or supernatural beings '' or `` some sort of ultimacy and transcendence that will provide norms and power for the rest of life '' .