Religious exclusivism is the doctrine or belief that only one particular religion or belief system is true.
Muslims believe that Islam is the original and primordial faith, or fitrah, that was revealed by Muhammad. Muslims maintain that previous messages and revelations have been partially changed or corrupted over time and consider the Quran to be the unaltered and the final revelation from Allah. Religious concepts and practices include the five pillars of Islam, which are basic concepts and obligatory acts of worship, and following Islamic law, which touches on virtually every aspect of life and society, encompassing everything from banking and welfare, to warfare and the environment.
Islam began its history with an exclusivist attitude toward polytheist religions, but an inclusivist attitude toward Christians and Jews. As people "of the Book," believers in the oneness of God were given the status of dimmi, conferring on them certain rights, including the right to practice their religions openly and not to be pressured to accept Islam.
In practice, however, neither the inclusion of Jews and Christians nor militant exclusivism toward "pagans" was always practiced. Trinitarian Christians were accused of idolatry because of their veneration of icons and were also sometimes treated as polytheists because of the doctrines of the Trinity and the Incarnation. As strict monotheists, Jews generally fared better than Christians under Islamic rule. Jews and Christians are viewed largely favorably as compared to any other religion.