Judaism, Christianity, and Islam are known as the three Abrahamic religions, meaning that, in addition to being monotheistic faiths that worship the same God, all three religions feature the Prophet Abraham in a foundational role. The nature of that role, however, is unique to each religion, and speaks to the other significant differences of belief between them.

Judaism

Judaism emerged as the monotheistic faith of the Israelite tribes of the ancient Middle East. As a faith, Judaism began when G-D revealed himself to the prophet Abraham in around the year 1800 B.C. Together, Abraham, along with his son Isaac and his grandson Jacob, represent the three Patriarchs of Judaism. It is from the narratives of their lives in the holy scriptures: the Torah, the Talmud, the Midrash, and the Tanakh, that Judaism derives its principal beliefs (see reference 2). Judaism is a non-hierarchical religion, and its spiritual leaders, called rabbis, are considered teachers. The holiest location in Judaism is the city of Jerusalem in the land of Israel, which Jews believe was given by G-D to Abraham and his descendants.

Christianity

The beliefs of Judaism are encapsulated in its holy texts, notably the Tanakh. Christianity similarly draws its beliefs from the Tanakh, which it calls the Old Testament, as well as from the New Testament, which includes texts about the life and teachings of Jesus. Whereas Judaism is non-hierarchical in the sense that it ascribes equal attention to all of the prophets and recognizes no other temporal human authorities, Christianity is founded on the belief that Jesus, the son of God, is the Messiah who brought the final word of God, while certain branches of Christianity do recognize temporal religious authorities, such as the role of the pope in Catholicism. Christianity includes the religious narratives of Judaism, while introducing Jesus Christ, who is strictly a historical figure in Judaism, as a focal point of worship. Since crucial moments in the life of Jesus unfolded in Jerusalem, this city is a holy site for Christians, as it also is for Jews and Muslims.

Islam

While Judaism and Christianity hold the same beliefs about the life of Abraham, Islam provides an alternative narrative. Muslims believe that Abraham found his way to the Arabian Peninsula with his son Ishmael, where they constructed a cubical structure around, called the Kabba, around a half-buried meteorite as a testament to the one true God. This location is in Islam's holiest city of Mecca, and it is a destination that all Muslims are obliged to visit on a pilgrimage called the Hajj as a pillar of their faith. While Islam acknowledges the same line of prophets as Christianity, including Jesus (though as a prophet and not as the Messiah), Muslims believe that God's final word was brought to the prophet Muhammad through the angel Gabriel in the year 610. Islamic society accepted Jews and Christians as fellow followers of the Abrahamic religions and recognized them a protected "dhimmi" status, acknowledging their freedom of religious worship.

Orthopraxy v. Orthodoxy

Judaism and Islam are religions of orthopraxy, meaning that faith is demonstrated to God by living a lifestyle that follows religious beliefs. Judaism and Islam both contain dietary laws, called Kosher and Halal, respectively. Religious law for Judaism is contained in the Torah, and for Islam in the Quran. Christianity is a religion of orthodoxy, meaning that faith is demonstrated by belief, specifically in the role of Jesus Christ as the son of God and the Messiah. Whereas visual anthropomorphic depictions of religious figures is forbidden in Judaism and Islam, some denominations of Christianity allow for iconography, for example in the stained glass windows of some Catholic churches, but these images are only for spiritual reflection and are not worshipped. Overall, given the complexity of each of the Abrahamic religions, there is not only overlapping of orthodoxy and orthopraxy, but significant procedural, doctrinal, and cultural variations within and between each religion that preclude generalizations.