When did Judaism become monotheistic?

The short version: in stages, over about three centuries, with the decisive step during the Babylonian exile. The Hebrew Bible contains all the stages side by side, because it was written and edited over the whole period, and the final editors kept older texts that assumed other gods existed. Historians distinguish three positions, and the date at which Judaism “became monotheistic” depends on which one is meant.^[1]​^[2]

Stage one: Yahweh among the gods (was early Israel polytheistic?)

The oldest evidence shows Yahweh as Israel’s chief god, not its only one. Psalm 82 opens with God standing “in the assembly of El”, judging “in the midst of the gods”, and sentencing them to die “like men”.^[3] The older reading of Deuteronomy 32:8–9, preserved at Qumran, has the Most High divide the nations among “the sons of God”, with Yahweh receiving Israel.^[4] Around 800 BCE travellers at Kuntillet ʿAjrud blessed one another “by Yahweh of Samaria and by his asherah”.^[5]

What it proves. In the ninth and early eighth centuries BCE, Israelite religion imagined a heaven with many divine beings, and some Israelites worshipped other deities beside Yahweh. No text of this period says that no other god exists. Consensus

Stage two: Yahweh alone

From the eighth century the demand changes. Hosea, in the northern kingdom, has Yahweh say: “You know no god but me, and besides me there is no saviour.”^[6] The first commandment, “You shall have no other gods before me”, forbids worship, not existence.^[7] Deuteronomy, whose core most scholars link to King Josiah’s reform of 622 BCE, demands loyalty to Yahweh alone in the language of an Assyrian vassal treaty, and its most famous verse, the Shema, probably meant in its original setting “Yahweh is our God, Yahweh alone”.^[8]​^[9] Josiah then removed the vessels of Baal, Asherah and the host of heaven from the Temple.^[10]

What it proves. The prophets and reformers of the eighth and seventh centuries demanded exclusive worship. They argued about which gods Israel should worship, not whether other gods existed. Majority

Morton Smith and Bernhard Lang described the people behind this demand as a “Yahweh-alone movement”: a minority of prophets, priests and officials who won royal backing under Hezekiah and Josiah and whose writings shaped the Bible.^[11]​^[12]​^[13] Jeremiah 44 shows they did not convince everyone: Judahite refugees in Egypt told the prophet that things had gone well while they made offerings to “the queen of heaven” and badly since they stopped.^[14] Majority

Stage three: no other god

Jerusalem fell to Babylon in 587/586 BCE.^[15] Among the exiles, an anonymous prophet whose words are preserved in Isaiah 40–55 made a new claim, repeatedly and without qualification:

ʾănî YHWH wĕʾên ʿôd, zûlātî ʾên ʾĕlōhîm

“I am Yahweh, and there is no other; besides me there is no god.”^[16]

The same prophet says Yahweh “forms light and creates darkness, makes peace and creates evil” (45:7), and mocks the gods of Babylon as wood and metal carried on pack animals.^[17]​^[18] Deuteronomy 4, an exilic addition to the book, says the same in prose: “Yahweh is God; there is no other besides him.”^[19]​^[1]

What it proves. This is the first unambiguous denial in the Bible that any other god exists. It answered the crisis of the exile: if Yahweh controls all history, Babylon’s victory was his doing, not his defeat, and the gods of the conquerors are nothing. Majority

Even this was recent enough to leave seams. The same chapter of Deuteronomy says that Yahweh allotted the sun, moon and stars to the other nations to worship (4:19).^[19]

The case on each side

In the exile (the majority view). Explicit denials of other gods first appear in Isaiah 40–55 and Deuteronomy 4; everything earlier assumes their existence. Mark Smith, Thomas Römer and Rainer Albertz hold versions of this view.^[1]​^[2]​^[20] Majority

Early, from Israel’s beginnings. Yehezkel Kaufmann argued that Israelite religion was different in kind from its neighbours’ from the start, and that the biblical writers did not even understand how polytheism worked. His strongest evidence is onomastic: Jeffrey Tigay found that Hebrew personal names in inscriptions and seals are built on Yahweh by a very wide margin. If Israelites had widely worshipped other gods, more of their children’s names would show it.^[21]​^[22] Contested

Never quite, in the Bible. Nathan MacDonald argues that “monotheism”, a word coined in the seventeenth century, misdescribes even Deuteronomy, whose claims are about Yahweh’s uniqueness and Israel’s loyalty rather than a philosophical denial of other divine beings; the Bible’s heaven stays full of angels, the host of heaven and, later, the satan.^[23] Peter Hayman made the same point about all of ancient Judaism: its God remained a king ruling a court of powerful heavenly beings.^[24] Contested

The traditional account. In rabbinic tradition Abraham recognised the one God and broke his father’s idols; at Sinai all Israel heard the commandment to have no other gods; and the prophets called the people back to what they had always been commanded.^[25] On this view the Bible’s long story of Israel turning to other gods is a story of unfaithfulness to an original monotheism, not of the road toward it. Consensus that this is the traditional view.

The traditional and critical readings agree on one point: the Bible itself depicts a long struggle between Yahweh and other gods. They differ on whether it was a falling away from monotheism or the path to it.

Was Judaism the first monotheistic religion?

Probably not the first experiment. In Egypt, the pharaoh Akhenaten (c. 1350–1335 BCE) promoted the exclusive worship of the sun disc, the Aten, and closed the temples of other gods; his reform was reversed after his death.^[26] Jan Assmann has traced how the memory of that suppressed revolution resurfaced in later Egyptian and Greek stories about Moses.^[27] Some scholars also see a tendency toward a single supreme god in the Zoroastrian Gathas, which present Ahura Mazda as the wise creator; Mary Boyce dated them before 1000 BCE, but their date is disputed and many scholars place them later.^[28] Neither became the long-lasting, text-based monotheism that Judaism developed, and there is no evidence that Akhenaten’s reform influenced Israel directly. Majority

Common misconceptions

• “The Ten Commandments teach monotheism.” “You shall have no other gods before me” forbids Israel to worship other gods. It is the classic statement of monolatry, which later readers understood as monotheism.
• “The Shema was always a statement that God is one.” In its seventh-century setting, Deuteronomy 6:4 probably meant that Yahweh alone was Israel’s god; later Jewish tradition read it as a statement of the unity and uniqueness of God, and in that sense it became the centre of Jewish prayer.^[8]
• “Monotheism means there are no other spiritual beings.” Jewish monotheism from the Persian period on included angels, named archangels and the satan, all subordinate to God (§5, §6). The satan of Job and the archangel Michael of Daniel serve the one God, and even the rebel angels of 1 Enoch are judged by him.^[29]​^[30]​^[31]

Why it matters

Monotheism was the most consequential religious idea to come out of ancient Judah, inherited by Christianity and Islam. Its history shows that it was not a starting point but a conclusion, reached by a small kingdom’s thinkers in the aftermath of their kingdom’s destruction, and that Judaism preserved the earlier stages in its own scripture.

For the exile and Second Isaiah, see Chapter 4: Exile and the Birth of Monotheism. For the prophets and Josiah’s reform, see Chapter 3: The Prophets and the Yahweh-Alone Movement. For Yahweh among the gods, see Chapter 2: Yahweh Among the Gods.