In the study of comparative religion, an Abrahamic religion is any of those religions deriving from a common ancient Semitic tradition and traced by their adherents to Abraham ("Father/Leader of many" Hebrew אַבְרָהָם Arabic ابراهيم), a patriarch whose life is narrated in the Hebrew Bible/Old Testament, and as a prophet in the Qur'an.
This forms a large group of related, largely monotheistic religions, generally held to include Judaism, Christianity, Islam, and the Bahá'í Faith (based upon Islam), and comprises about half of the world's religious adherents.
According to the Jewish tradition, Abraham was the first person to reject idolatry, hence he symbolically appears as the founder of monotheistic religions. In that sense, Abrahamic religion could be simply equated with monotheistic religion, but not all monotheistic religions are Abrahamic. In Islam he is considered as the first monotheist and is often refered to as Ibrahim al-Hanif or Abraham the Monotheist. The term, desert monotheism, is sometimes used for a similar purpose of comparison in historical contexts, but not for modern faiths.