Monotheism

Hear, O Israel: The LORD our God, the LORD is one.

— Deuteronomy 6:4

Monotheism is the belief that only one true and living God exists, the Creator, Owner, and Judge of everything that is, to the exclusion of every other claimed deity. Historic Christian monotheism is Trinitarian: the one divine essence is shared, undivided, by Father, Son, and Holy Spirit, three distinct persons rather than three separate Gods. This sets Christian monotheism apart from the strict unitarian monotheism of Judaism and Islam, which admit no plurality of persons within God, and from henotheism, which worships one god without denying that others exist.

Confessional Witness

The Reformed confessional family speaks with one voice here. The Westminster Confession (1646) and the Savoy Declaration (1658) both open their chapter “Of God, and of the Holy Trinity” with the words “there is but one only living and true God.”¹ The 1689 Second London Baptist Confession states the same doctrine in its own opening line: “The Lord our God is but one only living and true God; whose subsistence is in and of himself, infinite in being and perfection.”² The doctrine is not a Baptist distinctive; it is the Reformed tradition’s shared restatement of the church’s oldest conciliar confession, the Nicene Creed, which likewise opens: “We believe in one God, the Father almighty, maker of heaven and earth, of all things visible and invisible. And in one Lord Jesus Christ…”³

The confession’s added clause, “whose subsistence is in and of himself,” states God’s aseity: God does not depend on, or rank among, other beings; God is the one self-existent source of everything else that exists. Read alongside the Nicene Creed’s own pairing of “one God” with “one Lord Jesus Christ,” the confessional tradition treats the doctrine of the Trinity as a further, careful statement of what the one true God’s own inner life is like, developed within the doctrine of monotheism rather than set against it.

Biblical Basis

The doctrine’s classic statement is the Shema: “Hear, O Israel: The LORD our God, the LORD is one” (Deut. 6:4). Isaiah presses the same point as an exclusive claim of the LORD’s own mouth: “I am the first and I am the last; besides me there is no god” (Isa. 44:6; compare Isa. 43:10; 45:5-6, 21-22). The New Testament carries the same confession forward without dividing it: “there is no God but one” (1 Cor. 8:4-6), “there is one God, and there is one mediator between God and men, the man Christ Jesus” (1 Tim. 2:5), and Jesus himself names the Shema as “the most important” commandment (Mark 12:29-30). James adds a warning against treating the doctrine as merely notional: “You believe that God is one; you do well. Even the demons believe—and shudder” (James 2:19).

Doctrinal Significance

The doctrine grounds worship, truth, and morality together rather than leaving each to stand on its own. Bavinck traces how the early church, on its first appearance in the Greco-Roman world, argued for the “uniqueness of God” from every direction available to it: Scripture, the witness of conscience, the testimony of gentile philosophers and poets, and the observed unity of the world and of the human race. Bavinck describes the result as polytheism “overcome and deprived both religiously and scientifically of all its power”: “Polytheism fails to satisfy the human spirit; only confession about the one true God sustains religion, truth, and morality.”⁴ Where that confession weakens, Bavinck warns, “every form of superstition and idolatry makes a comeback” in some new guise, ancient polytheism’s modern substitutes included.⁴ The same logic drives Isaiah’s own argument in chapters 40-48: because the LORD alone is the transcendent Creator, he alone, and no idol, is worthy of worship.⁵

Historical Development

The early church against Greco-Roman polytheism

The church “made its debut in the gentile world” on the confession of one God, directly confronting “the popular polytheism of the Roman world.”⁴ Christian apologists pressed the case on every front available to them, and attacked what polytheism carried with it: “demonism and superstition, mantic and magic, the deification of humans and emperor worship, the theaters and the games.”⁴

Nicaea: monotheism restated in Trinitarian terms

The fourth-century crisis over Arius’s teaching forced the church to state, with new precision, how its inherited biblical monotheism could also be true of both the Father and the Son. The Council of Nicaea’s 325 creed answered by confessing “one God, the Father almighty,” and, in the same breath, “one Lord Jesus Christ… true God from true God.”³ The creed’s own structure makes the point: it states the Son’s full deity as a further unfolding of the confession of one God, in the same breath rather than as a separate claim added to it.

The tritheism charge and John Gill’s response (17th-18th century)

A notable post-Reformation English controversy over Trinitarian monotheism began in 1690, when William Sherlock published A Vindication of the Holy and Ever-Blessed Trinity, explaining the three persons by analogy to “three infinite minds.” In 1693 Robert South (1634-1716), Canon of Christ Church Cathedral, Oxford, replied anonymously that three infinite minds “necessarily infers three Gods”: on his reading, Sherlock’s own account of orthodoxy had collapsed into tritheism.⁶ The dispute ran on through pamphlets on both sides for the rest of the decade.

Writing decades later, the Particular Baptist theologian John Gill (1697-1771) took up the same standing charge in his mature dogmatics. Gill denied that Trinitarians believe in three Gods: the one divine essence, he wrote, is “undivided and common to the Father, Son, and Spirit,” not partitioned among them the way three human beings each possess a separate instance of human nature. “The Father is God, the Son is God, and the Holy Ghost is God, yet not that they are three Gods, but one God.”⁷ Gill grounded this unity in the same texts already cited above, the Shema and Isaiah’s exclusivity statements, reading them as establishing not merely that God is supreme but that God is numerically one.⁸

Opposing Views

Polytheism affirms the existence of multiple gods, typically organized into a pantheon with differing functions and powers. Henotheism is a distinct position: devotion to one god, usually a tribal or national deity, without denying that other gods exist for other peoples. Monotheism makes the stronger claim that no other god exists at all, and so rules out both.⁹

A modern critical alternative holds that Israel’s monotheism was a late development, evolving out of henotheism or polytheism over the course of Israel’s history, rather than an original revealed teaching. Bavinck rejects this account directly: “Israel’s religion did not evolve from henotheism to ethical monotheism but is rooted in the divine call of Abraham/Israel and God’s initiative in establishing a covenant with Israel.”¹⁰ Carter likewise declines to read the Old Testament through “an evolutionary metaphysics,” the approach of scholars such as Mark S. Smith; following John Oswalt and John Currid, he instead reads Israel’s Scriptures as “revealed polemical correction of pagan religious ideas” from the outset, rather than a product that gradually emerged from those same ideas.⁵

Objections and Responses

Doesn’t confessing the Father, Son, and Holy Spirit as each fully God amount to tritheism? This is the objection Robert South pressed against Sherlock in 1693, and it recurs whenever the Trinity is explained by analogy to three separate minds or beings.⁶ The Reformed answer, stated by Gill against the same charge, is that the persons do not each possess a separate divine essence the way three individual men each possess a separate instance of human nature; they share one undivided essence in common.⁷ Put more sharply, the Trinity’s unity is “a qualitative one, not a quantitative one”: a unity of shared nature, not a headcount of three distinct beings.¹¹

Related Doctrines

References

The Westminster Confession of Faith (1646), chap. 2, para. 1. ↩
The Second London Baptist Confession of Faith (1689), chap. 2, “Of God and of the Holy Trinity,” para. 1. ↩
Ronald E. Heine, Classical Christian Doctrine: Introducing the Essentials of the Ancient Faith (Grand Rapids: Baker Academic, 2013), chap. 3, “The Lord Our God Is One,” 24. ↩ ↩²
Herman Bavinck, Reformed Dogmatics: Abridged in One Volume, ed. John Bolt (Grand Rapids: Baker Academic, 2011), chap. 8, “The Living, Acting God.” ↩ ↩² ↩³ ↩⁴
Craig A. Carter, “God as the One Who Alone Is to Be Worshiped (Isa. 41-48),” in Contemplating God with the Great Tradition: Recovering Trinitarian Classical Theism (Grand Rapids: Baker Academic, 2021), chap. 6. ↩ ↩²
Steven Tshombe Godet, “The Trinitarian Crisis of the Long Eighteenth Century,” in “The Trinitarian Theology of John Gill (1697-1771): Context, Sources, and Controversy” (PhD diss., The Southern Baptist Theological Seminary, 2015), 94-95. ↩ ↩²
Steven Tshombe Godet, “Gill’s Doctrine of the Trinity: The Unity of God and the Plurality in the Godhead,” in “The Trinitarian Theology of John Gill (1697-1771): Context, Sources, and Controversy” (PhD diss., The Southern Baptist Theological Seminary, 2015), 222. ↩ ↩²
Godet, “Gill’s Doctrine of the Trinity,” 214-215. ↩
Louis Berkhof, Systematic Theology (London: Banner of Truth Trust, 1969), pt. 1, “The Doctrine of God.” ↩
Bavinck, chap. 7, “Knowing God.” ↩
Thomas H. McCall, Which Trinity? Whose Monotheism?, quoted in Keith Wesley Goad, “Contemporary Subordinationist and Equivalence Models: Tampering with the Trinity,” in “Trinitarian Grammars: A Comparison of Gregory of Nazianzus and Some Contemporary Models” (PhD diss., The Southern Baptist Theological Seminary, 2010), 276. ↩