Two questions come up again and again about the Abrahamic religions, Judaism, Mandaeism, Christianity and Islam: how their founding figures are related, and what the traditions hold in common. The family tree below answers the first from the genealogies each tradition keeps; the diagram after it answers the second.
The family of Abraham
Genesis traces Abraham back through Shem to Noah, and gives him two sons: Ishmael, born to Hagar, and Isaac, born to Sarah in old age.1 It names twelve sons of Ishmael, the first two being Nebaioth and Kedar, and twelve sons of Isaac’s son Jacob, the fathers of the tribes of Israel.2 From the tribe of Levi came Moses and Aaron and the priesthood; from the tribe of Judah came David. The Gospel of Matthew opens by calling Jesus the son of David and the son of Abraham, and Luke places John the Baptist in a priestly family descended from Aaron.3
The Qur’an keeps both sons in view. It names Ismāʿīl and Isḥāq together among the prophets, pairs Ismāʿīl with his father in raising the foundations of the Kaaba, and records Jacob’s sons pledging to worship the God of Ibrāhīm, Ismāʿīl and Isḥāq.4 The earliest biography of Muhammad traces his descent to Ismāʿīl through ʿAdnān, ancestor of the northern Arabs, by way of Ismāʿīl’s eldest son Nābit, the biblical Nebaioth.5 On this reckoning the two sons of Abraham head the two lines that carried prophecy: through Isaac to Moses, David, John and Jesus, and through Ishmael to Muhammad.
The tree also places the Mandaeans, on a line of their own beside Shem. They trace their descent from Seth through Enoch to Shem and do not count Abraham among their prophets; the dotted line joins them to John the Baptist, whom they honour as their great teacher.6 See Kedar, the Arabs and the prophets for the line of Ishmael in more detail.
What the traditions share
The four traditions agree on more than they differ. All four worship one God, hold that God has spoken through revealed scripture, and expect a judgement after death.7 Judaism, Christianity and Islam also look to Abraham as their forefather and honour Moses and the prophets. Beyond that common ground, pairs of traditions share what the others do not. Judaism and Christianity share the Hebrew Bible as scripture. Christianity and Islam share Jesus as the Messiah, born of a virgin, who will return.8 Judaism and Islam share a God whose oneness admits no division, and a religious law that governs daily life, diet and circumcision.9 Mandaeism joins Christianity and Islam in honouring John the Baptist, and shares baptism with Christianity, though its own baptism is repeated throughout life and always in running water.
Islam holds a region of its own with Judaism and another with Christianity, and joins Christianity and Mandaeism in the honour given to John the Baptist. The distinctive claims sit at the edges: for Judaism, Israel as the covenant people and the Talmud; for Mandaeism, repeated baptism in running water and the Ginza Rabba; for Christianity, the Trinity and the crucifixion as atonement; for Islam, Muhammad as the final prophet and the Qur’an.10
See Comparative studies for a fuller comparison.
Further reading: Who was Abraham?, The path of Abraham in the Qur’an, Jesus across the traditions, The symbols of the four traditions.
Notes
- Genesis 11:10-26; 16:15; 21:2-3. ↩
- Genesis 25:13-16; 35:22-26. ↩
- Matthew 1:1; Luke 1:5. ↩
- Qur’an 2:127, 133, 136; 19:54. ↩
- Ibn Isḥāq, The Life of Muhammad, trans. A. Guillaume (London: Oxford University Press, 1955), pp. 3-4. ↩
- Maurice Hines, Interpretatio Islamica and the Unraveling of the Ancient Sabian Mysteries (MA thesis, American University in Cairo, 2023), p. 73; E. S. Drower, The Mandaeans of Iraq and Iran (Oxford: Clarendon Press, 1937), pp. 265-266. ↩
- Deuteronomy 6:4; Mark 12:29; Qur’an 112:1-4; for Mandaeism, Drower, op. cit., pp. 73, 95. ↩
- Qur’an 3:45; 4:157-159; 19:19-21. ↩
- Qur’an 4:171; 5:73; Deuteronomy 6:4. ↩
- Qur’an 33:40. ↩