Over the past several months, I have found myself returning to the same question in conversations, lectures, podcasts, and online discussions: What does Scripture mean by “one God”?
The question is not academic in the pejorative sense. It determines how we read hundreds of passages spread across the canon. It shapes how we understand Israel’s confession, the identity of Jesus, the language of the New Testament, and eventually the development of Christian theology, such as the Trinity.
What follows is not intended as a complete doctrine of God or a comprehensive history of Christian theology. It is an attempt to follow the biblical confession that “the LORD is one” from its origins in Israel’s Scriptures through its reception in the earliest Christian centuries.
The difficulty begins with the text itself. Moses declares, “The LORD is one” (Deut. 6:4). Isaiah proclaims, “I am the LORD, and there is no other” (Isa. 45:5). Paul writes, “For us there is one God, the Father” (1 Cor. 8:6). Yet the same Scriptures speak of “the gods” (Ex. 15:11), God’s heavenly council (Ps. 82:1), “sons of God” (Job 1:6), and even “many ‘gods’ and many ‘lords’” (1 Cor. 8:5).
At this point, modern readers usually reach for a familiar category. We ask whether Israel was monotheistic. The word monotheism is neither biblical nor ancient Jewish. It does not appear in the Old Testament, the New Testament, the Septuagint, the Dead Sea Scrolls, Philo, Josephus, or the early church fathers. It emerged in the seventeenth century, when the English theologian and philosopher Henry More coined monotheismus to distinguish belief in one God from polytheism, atheism, and other competing religious systems.
The word proved useful. It also encouraged readers to organize the biblical evidence around a particular question: How many gods exist? Statements about God’s uniqueness, Israel’s exclusive worship, and the Father’s primacy were increasingly gathered beneath a single conclusion: only one God exists.
Yet those are not obviously the same kind of claim. When Scripture declares that “the LORD is one,” is it making a statement about the number of divine beings that exist? Or about the exclusive worship owed to Israel’s God? Or about the unique source and identity of the Godhead itself?
And while these claims are related and may overlap, it is helpful to distinguish them by name: monotheism, the conviction that only one God exists; monolatry, the exclusive worship of one God; and monarchia, the confession that divine unity is grounded in one source or principle.
1. Reading Deuteronomy on Its Own Terms
If this essay begins by asking what Scripture means when it declares that “the LORD is one,” the obvious place to begin is Deuteronomy itself.
Few studies have shaped this discussion more than Nathan MacDonald’s Deuteronomy and the Meaning of “Monotheism.” Originally published as his doctoral dissertation, the book asks whether monotheism is even the right category for reading Deuteronomy. Instead of starting with a definition of monotheism and looking for it in the text, MacDonald starts with the text itself. His conclusion is careful but significant. He argues that “the term ‘monotheism’ does not adequately describe the beliefs and practices in Deuteronomy.” Instead, “an often quite different picture emerges,” in which “love towards YHWH, the demanding nature of remembering YHWH, and the problem of human propensity to idolatry can again be seen as central to the confession that ‘YHWH is one.’”
The structure of Deuteronomy supports his conclusion. Israel confesses, “Hear, O Israel: The LORD our God, the LORD is one.” Moses immediately follows with a command: “You shall love the LORD your God with all your heart and with all your soul and with all your might” (Deut. 6:4–5). The chapters that follow continue that same emphasis. Israel is told to remember the LORD’s mighty acts, teach His words to their children, destroy the places of false worship, refuse the temptation to follow other gods, and remain faithful to the covenant He made with them. These themes appear again and again. Together they shape what it means for Israel to confess that the LORD is one.
Read in this context, the Shema is more than a theological statement. It stands at the center of Israel’s covenant life. It grounds Israel’s love, worship, memory, and obedience. The confession identifies the God to whom Israel belongs and therefore the God to whom Israel owes undivided allegiance. Moses is not simply defining God. He is forming a faithful people.
That shifts the question. Instead of beginning with the number of divine beings that exist, Deuteronomy directs our attention to the God who redeemed Israel, entered into covenant with her, and therefore alone deserves her love and worship. Read on its own terms, the confession that “the LORD is one” functions first as a declaration of exclusive covenant allegiance.
2. The Language of Creation
Reading Deuteronomy on its own terms reveals something important. The confession that “the LORD is one” stands at the center of Israel’s covenant life. It calls God’s people to exclusive love, faithful remembrance, and undivided worship. Any account of God’s oneness should begin there.
Deuteronomy, however, is not the whole story. As we continue reading the Old Testament, another pattern begins to emerge. Alongside passages concerned with covenant loyalty are others that explain God’s uniqueness by pointing to His relationship with the whole created order.
Isaiah is the clearest example. As Israel faces exile, the prophet repeatedly describes the LORD as the one who “created the heavens,” “stretched out the earth,” “formed the mountains,” and “made all things.” These descriptions appear alongside familiar declarations such as, “I am the LORD, and there is no other.” That pairing is difficult to ignore. Isaiah does not simply declare that the LORD is unique. He explains why. The LORD alone created all things. His rule extends beyond Israel because His creative work extends beyond Israel.
Nor is Isaiah alone. Genesis opens with the creation of heaven and earth before it introduces Abraham or the covenant people. The Psalms celebrate the LORD’s kingship by returning again and again to His work as Maker of heaven and earth. Jeremiah declares that the gods who did not make the heavens and the earth “shall perish.” The biblical writers repeatedly distinguish the LORD from every rival by appealing to creation itself. The Creator stands over everything He has made.
That observation pushes the conversation further. Deuteronomy teaches Israel whom she must worship. Isaiah and the rest of the Old Testament begin explaining why the LORD alone deserves that worship. Again and again, God’s uniqueness is grounded not only in His covenant with Israel but also in His relationship to the whole created order. He alone made heaven and earth. He alone gives life. He alone rules over all that exists.
The biblical emphasis on God as Creator would also prove decisive for later theology. Although the doctrine of creatio ex nihilo is not explicitly articulated in the Old Testament, many scholars trace its development through the Second Temple period, with 2 Maccabees 7:28 often cited as an important witness. By the second century, Christian theologians such as Theophilus of Antioch, Irenaeus, and Tertullian would give the doctrine explicit expression, particularly in response to Middle Platonic and Gnostic accounts of the world’s origin. By distinguishing the uncreated Creator from everything that exists because He freely brought it into being, creatio ex nihilo became one of the clearest theological expressions of the biblical pattern already emerging in Isaiah and the rest of the Old Testament.
3. Reading the Canon Together
What exactly is Isaiah denying when he mocks idols? What exactly is Paul denying when he says, “an idol has no real existence”? Those questions deserve a slower answer than they often receive.
Isaiah’s polemic against idols reaches its fullest expression in chapters 40–48. A craftsman cuts down a tree, burns part of it for fuel, and fashions the remainder into an object of worship (Isa. 44:9–20). The idol is the work of human hands. It cannot speak. It cannot save. Yet Isaiah’s argument does not end with the manufacture of idols. Throughout these same chapters, the prophet repeatedly identifies the LORD as the one “who made all things,” who “alone stretched out the heavens,” who “spread out the earth by myself” (Isa. 44:24), who “made the earth and created man on it” (Isa. 45:12), and who “declares the end from the beginning” (Isa. 46:10). The contrast is not simply between a real God and imaginary gods. It is between the one who created, rules, and redeems, and those who do none of these things.
Paul’s discussion of food offered to idols follows a similar pattern. He begins, “we know that ‘an idol has no real existence,’ and that ‘there is no God but one’” (1 Cor. 8:4). His next sentence continues the argument. “For although there may be so called gods in heaven or on earth, as indeed there are many ‘gods’ and many ‘lords,’ yet for us there is one God, the Father, from whom are all things and for whom we exist” (1 Cor. 8:5–6). Whatever Paul means by the “many gods and many lords,” he distinguishes the one God by His unique relationship to creation. The Father is the one “from whom are all things.” A few chapters later, Paul adds another piece to the discussion when he writes that pagan sacrifices are offered “to demons and not to God” (1 Cor. 10:20). The idol itself is nothing. The worship is not.
Other New Testament writers employ Israel’s confession differently. Romans 3:30 appeals to the oneness of God as the basis for His impartial justification of both Jew and Gentile. James 2:19 invokes the Shema to expose the emptiness of a faith that consists only of correct belief. Neither passage attempts to explain the nature of divine existence. Both assume Israel’s confession and apply it within covenantal and ethical arguments.
Taken together, these texts reveal a consistent pattern. When the biblical authors explain why the God of Israel alone is God, they repeatedly appeal to characteristics that belong to Him alone. He alone created heaven and earth. He alone directs history. He alone redeems His people. He alone stands as the source of all things. Scripture certainly affirms the uniqueness of Israel’s God. The question is how that uniqueness is expressed. Again and again, the biblical writers answer by pointing to what only the God of Israel does.
4. The Language of Monarchia
The earliest Christian discussions of God’s unity are often framed in the language of monarchia. The Greek word monarchia combines monos (”one” or “alone”) with archē, a term whose semantic range includes beginning, source, first principle, authority, and rule. The English word monarchy preserves only part of this range. In Greek, monarchia could refer to sole rule, but it could also denote a single source or first principle. This breadth of meaning made the term well suited to express themes that recur throughout Scripture. The one God alone creates. He alone rules. He alone stands as the source of all things.
The vocabulary itself was not a Christian invention. Greek political writers had long employed monarchia in contrast to forms of divided rule, and Jewish authors were already using the term before the rise of Christianity. Philo of Alexandria, for example, contrasts polyarchia with the worship of the one divine ruler, arguing that true religion acknowledges God’s unique monarchia rather than a plurality of competing powers (On the Decalogue 52–65). The language already belonged to the intellectual world in which Christian theology emerged.
The second- and third-century fathers adopted the same vocabulary. Defending the unity of the Creator against Valentinian speculation, Irenaeus repeatedly insists that there is one God who alone created heaven and earth and rejects every attempt to multiply first principles (Against Heresies II.1; II.28; IV.20). Tertullian makes the point even more explicitly. Responding to Praxeas, he writes, Monarchiam tenemus—”We hold the monarchy” (Against Praxeas 3). His argument is striking. The confession of Father, Son, and Holy Spirit does not divide God’s monarchia or introduce multiple sources of deity. Rather, the Trinity preserves the one divine monarchia because the Son and Spirit proceed from the Father without establishing rival principles.
Origen likewise speaks of the Father’s monarchia while maintaining the eternal generation of the Son (On First Principles I.2; Commentary on John II). The Cappadocian Fathers continued this pattern. Basil, Gregory Nazianzen, and Gregory of Nyssa consistently grounded the unity of the Trinity in the Father as the one archē, not because the Son or Spirit are lesser beings, but because the Father is the eternal source within the Godhead (Gregory Nazianzen, Oration 42.15; Gregory of Nyssa, Against Eunomius). Across these writers, monarchia functions as a theological description of God’s unique identity as the one source and sovereign Lord.
This continuity is historically significant because modern readers often encounter the word only through the label Monarchianism. The label is misleading if it suggests that monarchia itself was controversial. The controversy was not whether God possesses a monarchia but how that monarchia should be understood. Modalists appealed to the divine monarchia by collapsing the distinction between Father and Son. Orthodox theologians answered by insisting that the Father’s monarchia is preserved precisely through the eternal relations of Father, Son, and Spirit. Tertullian’s Against Praxeas is therefore not a rejection of monarchia but a defense of it.
Conclusion
The subsequent history of theological vocabulary followed a different course. The language of monarchia gradually receded, while the language of monotheism eventually emerged in the seventeenth century. When Henry More coined monotheismus, the term served a new intellectual task: distinguishing religions according to the number of gods they affirmed. It proved to be a useful category. It also encouraged later readers to gather a wide range of biblical claims beneath a single question: How many gods exist?
That is a legitimate theological question. It is not always the question Scripture is asking. Deuteronomy presents the confession that “the LORD is one” as the foundation of Israel’s exclusive covenant allegiance. Isaiah repeatedly identifies the LORD as the one who alone created heaven and earth, governs history, and redeems His people. Paul identifies the Father as the one “from whom are all things and for whom we exist,” even while acknowledging the existence of “many ‘gods’ and many ‘lords.’” These are not competing answers. They are complementary ways of identifying the God of Israel.
This, perhaps, explains why the earliest Christian theologians so naturally spoke of the monarchia of God. They inherited a canon that repeatedly identified God by His unrivaled identity as Creator, source, ruler, and Lord. Monarchia gave them a way to describe those patterns together. Monotheism, by contrast, would arise much later within a different historical conversation.
None of this renders the language of monotheism false or unnecessary. Christians rightly confess that there is but one God. The argument of this essay is simply that the biblical witness is richer than that single category can express. Scripture does not merely tell us that God is one. It tells us who the one God is. He alone is to be worshiped. He alone created heaven and earth. He alone rules history. He alone is the source from whom all things come and the Lord to whom all things belong.
Further Reading
If this essay has sparked your interest, the following works are excellent places to continue exploring these questions. Both are freely available online.
Nathan MacDonald, One God or One Lord? Deuteronomy and the Meaning of “Monotheism” (Ph.D. thesis, Durham University, 2001).
Daniel O. McClellan, “Monotheism—Still a Misused Word in Jewish Studies?”