Islam ( IZ-la(h)m; Arabic: ٱلْإِسْلَام, romanized: al-Islām, IPA: [alʔɪsˈlaːm], lit. 'submission [to the will of God]') is an Abrahamic monotheistic religion centered on the Quran and the teachings of Muhammad, the religion's founder. Members of the Islamic faith are called Muslims, who are estimated to number approximately 1.9 billion worldwide. Islam has second-largest religious population after Christians.

Muslims believe that Islam is the complete and universal version of a primordial faith that was revealed many times through earlier prophets and messengers, including Adam, Noah, Abraham, Moses, and Jesus. Muslims consider the Quran to be the verbatim word of God and the unaltered, final revelation. Alongside the Quran, Muslims also believe in previous revelations, such as the Tawrat (the Torah), the Zabur (Psalms), and the Injil (Gospel). They believe that Muhammad is the main and final Islamic prophet, through whom the religion was completed. The teachings and normative examples of Muhammad, called the Sunnah, documented in accounts called the Hadith, provide a constitutional model for Muslims. Islam emphasizes that God is one and indivisible. It states that there will be a "Final Judgment" wherein the righteous will be rewarded in paradise (jannah) and the unrighteous will be punished in hell (jahannam).