With Christianity and Islam as the two dominant religions in today’s world, most assume that, if there is a god, there is only one. However, the vast majority of world religions today believe in multiple gods. Even in the ancient Middle East, the world from which these two major religions and Judaism emerged, the belief in monotheism was a relative newcomer to the religious landscape. For example, the Hittites of Anatolia (modern Turkey) proudly boasted of their three thousand gods. How did this idea of monotheism emerge against the grain and gain such momentum? First, a disclaimer: I am not attempting to detail whether in fact there is one god, many gods or none. Instead, I want to trace the emergence of people’s belief in a single god.

In the minds of ancient Middle Eastern people, including those in ancient Israel, many gods existed. Rather than being alone in the divine world, Yahweh, later known as God to Jews and Christians and Allah to Muslims, is presented as the patron god of the family of Abraham, Isaac and Jacob in the patriarchal and Exodus narratives of the Bible (Gen 26:24; 28:13; 32:9; 48:15; Exod 3:6, 15, 16; 4:5) and later of the nation of Israel (Exod 5:1; 24:10; 32:27; 34:23). In other words, Yahweh was likely understood as one among many patron and national deities throughout the ancient Middle East (Jdg 11:24). How then did Yahweh move in the minds of his worshipers from god to God? How did Yahweh evolve from the god of a fairly minor people group to the supreme god of the universe? Perhaps even more drastically, how did Yahweh transition from being the supreme god of the universe to the only one in the universe?

In fact, Yahweh’s emergence as a major player on the divine scene mirrored those of two other deities, Marduk and Assur, the primary gods of the ancient Babylonian and Assyrian empires. A look at their rise helps us to understand both Yahweh’s emergence from obscure beginnings and the corresponding emergence of monotheism. Traditionally, deities in the ancient Middle East had specialties, often controlling one or more areas of the world considered important. For example, in various cultures, Shamash, Shapash, The Sun Goddess of Arinna and Re all were associated with the sun, while Adad, Baal, Tessub and Seth controlled the storm. Like humans, gods competed for supremacy often through combat (for example, Ninurta and Anzu in Mesopotamia, Baal and Yamm at Ugarit, the Weather God and the descendants of Illuyanka in Hittite Anatolia, and Horus and Seth in Egypt).

Before his meteoric rise, Marduk was the relatively obscure god of a relatively obscure place. When Babylon moved from a local backwater to becoming the heart of a major empire, Marduk was in need of some creative rebranding to make him a suitable king of the gods. Like other major ancient Middle Eastern gods, Marduk too conquered an unconquerable foe (in his case, the monstrous Tiamat in the great epic Enuma elish). However, his traditional powers, presumably associated with canal digging, would not be sufficient. His public relations team went to work to expand his profile, employing a business model similar to modern megastores like Amazon.com and Walmart. Rather than claim that other deities did not exist or offer new divine powers, Marduk demonstrated his superiority by claiming for himself the other deities’ previously exclusive specialties (such as in his accumulation of 50 names). As a result, Marduk became the one-stop-shop god, who justified his status as the king of the gods, the best among many, by being able to do in one person all that the other gods could do. Assyria later followed suit in promoting Assur as king of the gods, who likewise rose from obscurity to become the one-stop-shop god. Throughout the histories of Babylonia and Assyria (and until the fall of Israel), Assur and Marduk continued to vie for supremacy with megastore-like rhetoric.

Like Marduk and Assur, Yahweh rose from relative obscurity. Like them, he did not offer any substantially new powers. Instead, the biblical innovation lay in combining pre-existing elements in a new way. While in Mesopotamia the goal was to legitimize the kingships of Marduk and Assur, in Israel the goal was more ambitious still, to promote exclusive worship of Yahweh (monolatry, not yet monotheism). In essence, they aimed to corner the Israelite market. To accomplish this goal, biblical authors for the most part did not argue that Yahweh was the only deity (see the potential exceptions in Deut 4 and Isa 40-48, both prompted by exceptional circumstances) or invent new powers. Rather, in order to convince the people that it was worthwhile to serve Yahweh exclusively, they presented him as possessing all the competencies of the other gods. Yahweh supporters essentially argued that he was a one-stop-god, who offered in one place all of the goods and services that the other gods offered collectively. For example, he served as an indomitable warrior (Exod 15) and creator (Gen 1), the bringer of fertility (Hos 2), head of the divine council (1 Sam 22:19) and controller of weather and nature (Psalm 29), including solar elements (Psalm 19). He even partook of stereotypically feminine aspects such as childbearing (Isa 46). Such a marketing strategy was necessary, for if Yahweh were unable to meet all of the people’s needs, they would be tempted to shop elsewhere. In short, biblical authors used their powers of persuasion to convince the people to take their business to Yahweh and no one else.

This goal of exclusive worship especially came under threat with the defeat of the nation and its exile at the hands of the Babylonians. In the face of apparent divine failure, exile and the confrontation with the high god of another system that spanned the Middle East in Marduk, the Bible again had to up its game. Whereas other gods (including Marduk and Assur) fell into obscurity with the fall of their nations, Yahweh worship survived and eventually expanded to form the basis for the world’s great monotheisms. In fact, its rhetoric was so successful that biblical religion is the only one from the ancient Middle Eastern world that is still practiced today. In order to inspire continued exclusive worship, Yahweh worshippers had to be convinced that he was superior to Marduk, that Yahweh could still meet all of their needs. In essence, Yahweh’s power had to be inversely proportional to that of his people. In order to be worthy of exclusive devotion with such competition, Yahweh was recast as the universal high god with no cosmic rival, rather than just the high god of the Israelite system. The god of Israel then became the supreme god of everyone and everywhere (Isa 40-48).

This pursuit of exclusive Israelite worship also had important implications on the divine world and its hierarchy. In Mesopotamia, the divine sphere had three tiers: 1) Marduk or Assur as high god, who functioned like a one-stop-shop god; 2) a second tier of multiple major gods with important specializations like the sun, weather, the sea and death, who acknowledged the supremacy of the high god; 3) and a third tier of various minor, servant deities. With the goal of exclusive Yahweh worship, the Bible had no room for potential competitors. Thus, it turned its rhetoric to expelling from the market the middle gods—major gods who possessed an important competency, like the storm-god Baal—such that only Yahweh the high god and the minor gods remained (including the gods, sons of god, the divine council, angels, the destroyer, cherubim and seraphim). In order to ensure that they too were no threat, they were not given names, personalities or families. They were simply described by their job title or category and subordinate status to Yahweh, essentially existing only as employees of Yahweh(.com).

At the end of the Hebrew Bible and into early Judaism and Christianity, the momentum of Yahweh’s supremacy caused a further reshuffling of the cosmic deck. The disparate minor god category was given a name, angels (literally “messengers”) even though most of its members were not messengers (see the equation of the sons of god and angels in Dan 3:25-28). By eliminating the middle tier and redefining the lower divine tier, the biblical writers essentially reduced the members of the god category to one, Yahweh, who as the unique member of the species moved from god to God.

Since they no longer posed a threat to Yahweh, angels began to gain individuality, leading to the explosion of interest in the angelic and demonic worlds in late Second Temple times. The shift to a single-god system led to another late Second Temple split with seeds in Genesis 6 and a full flowering in the Christian New Testament: the lowest divine tier further divided into good angels and bad angels or demons (see, for example, Matt 25:41; Rev 12:7-9). These beings fight not over supremacy in heaven, but rather over the souls of humanity. This final movement established the basic framework shared by Christian and Islamic monotheism—a single, universal god whose rule is contested by demonic figures.