A Muslim, also spelled Moslem, is an adherent of Islam, a monotheistic Abrahamic religion based on the Qur'an—which Muslims consider the verbatim word of God as revealed to prophet Muhammad—and, with lesser authority than the Qur'an, the teachings and practices of Muhammad as recorded in traditional accounts, called hadith. "Muslim" is an Arabic word meaning "one who submits to God".

Muslims believe that there is not other God but the one true God who is referred to with the name Allah. God is eternal, transcendent, absolutely one (the doctrine of tawhid, or strict or simple monotheism), and incomparable; that he is self-sustaining, who begets not nor was begotten. Muslim beliefs regarding God are summed up in chapter 112 of the Qur'an, al-Ikhlas, "the chapter of purity". Muslims also believe that Islam is the complete and universal version of a primordial faith that was revealed at many times and places before, including through the prophets Abraham, Moses and Jesus. Muslims maintain that previous messages and revelations have been partially changed or corrupted over time, but consider the Qur'an to be both unaltered and the final revelation from God—Final Testament.