Abrahamic religion spread globally through Christianity being adopted by the Roman Empire in the 4th century and Islam by the Islamic Empires from the 7th century. Today the Abrahamic religions are one of the major divisions in comparative religion (along with Indian, Iranian, and East Asian religions). The major Abrahamic religions in chronological order of founding are Judaism (the base of the other two religions) in the 7th century BCE, Christianity in the 1st century CE, and Islam in the 7th century CE.
Christianity, Islam, and Judaism are the Abrahamic religions with the greatest numbers of adherents. Abrahamic religions with fewer adherents include the faiths descended from Yazdânism (the Yezidi, Yarsani faiths), Samaritanism, the Druze faith, Bábism, [self-published source] the Bahá'í Faith, and Rastafari.
As of 2005, estimates classified 54% (3.6 billion people) of the world's population as adherents of an Abrahamic religion, about 32% as adherents of other religions, and 16% as adherents of no organized religion. Christianity claims 33% of the world's population, Islam has 21%, Judaism has 0.2% and the Bahá'í Faith represents around 0.1%.