Is God Unique? The Oneness of God Across Judaism, Christianity, and Islam

Jewish theology places the uniqueness of God at its absolute center. The foundational declaration is the Shema, drawn from Deuteronomy 6:4, which has been recited twice daily for millennia and is considered the core confession of Jewish faith Deuteronomy 6:4. There is no hedging here—the LORD is declared one, and rabbinic tradition (e.g., Maimonides in his Mishneh Torah, 12th century) elaborated this into the first of his Thirteen Principles: God is the Creator and Guide of all, and He alone is God.

The Psalms reinforce this with poetic force. Psalm 86:8 acknowledges that other peoples may speak of 'gods,' but none of those beings bear any resemblance to Israel's God in character or deed Psalms 86:8. This isn't a soft pluralism—it's a categorical denial of any rival deity's legitimacy.

The prophetic and historical literature presses the point further. Both 2 Samuel 7:22 and 1 Chronicles 17:20 use nearly identical language—'there is none like You and there is no other God but You'—suggesting this was a liturgical formula deeply embedded in Israelite worship 2 Samuel 7:221 Chronicles 17:20. And Zechariah 14:9 looks forward to an eschatological moment when this truth will be universally recognized: one God, one name, sovereign over all the earth Zechariah 14:9.

It's worth noting that some scholars, like Mark S. Smith in The Origins of Biblical Monotheism (2001), argue that early Israelite religion was henotheistic before becoming strictly monotheistic—but by the Second Temple period, Jewish theology had firmly settled on absolute, exclusive divine uniqueness.

Christianity inherits the Jewish affirmation of one God unreservedly. The New Testament doesn't abandon monotheism—it reaffirms it, even while introducing the distinctly Christian understanding of God as Father, Son, and Holy Spirit. Paul's letter to the Corinthians is a key text: 'to us there is but one God, the Father, of whom are all things' 1 Corinthians 8:6. Paul wrote this in a Greco-Roman context saturated with polytheism, and his insistence on one God was a countercultural theological claim.

The complication, of course, is the Trinity. Classical Christian theologians—Athanasius (4th century), Augustine (De Trinitate, c. 400 CE), and later Thomas Aquinas (Summa Theologiae, 13th century)—all insisted that Trinitarian doctrine does not compromise monotheism. The three persons share one divine essence (ousia), so there are not three gods but one God in three persons. This is the orthodox position affirmed by the Council of Nicaea (325 CE) and the Council of Constantinople (381 CE).

Critics within other traditions—and some within Christianity itself, such as Unitarians—argue that the Trinity functionally introduces plurality into God. But mainstream Christianity holds firmly that God's uniqueness is absolute: there is no other God, no comparable divine being, and no rival to the one Creator. The Old Testament passages affirming divine uniqueness (Deuteronomy 6:4, Psalm 86:8) are received as Christian scripture too Deuteronomy 6:4Psalms 86:8.

In Islam, the oneness of God—tawhid—isn't just one doctrine among many; it's the organizing principle of the entire faith. The Quran returns to it relentlessly. Surah Al-Baqarah (2:163) states it plainly: 'your god is one God. There is no deity [worthy of worship] except Him' Quran 2:163. Surah Ta-Ha (20:98) echoes this: 'Your god is only Allāh, except for whom there is no deity' Quran 20:98.

What makes the Quranic treatment distinctive is its polemical edge. Surah Sad (38:5) records the scoffing of Meccan polytheists: 'Has he made the gods [only] one God? Indeed, this is a curious thing' Quran 38:5. The Quran presents their mockery as evidence of their spiritual blindness—the very thing they found absurd is the central truth of existence.

Islamic theology, developed by scholars like Al-Ash'ari (10th century) and later Ibn Taymiyyah (14th century), distinguishes several dimensions of tawhid: oneness of lordship (rububiyyah), oneness of worship (uluhiyyah), and oneness of names and attributes (asma wa sifat). Associating partners with God—shirk—is identified in the Quran as the one unforgivable sin if maintained until death. This makes divine uniqueness not merely a theological proposition but a moral and salvific imperative.

Islam explicitly rejects the Christian Trinity and the Jewish concept of God having a 'son' as violations of tawhid, though it affirms that Jews and Christians originally received genuine monotheistic revelation.

Judaism centrally proclaims the oneness and uniqueness of God in the Shema: “Hear, O Israel: The LORD our God is one LORD,” affirming that Israel’s God is singular and incomparable Deuteronomy 6:4.

This uniqueness is repeatedly affirmed: “Among the gods there is none like unto thee, O Lord,” which denies any rival deity’s likeness or works Psalms 86:8.

Historical prayers in the Tanakh echo the same: “There is none like You, and there is no other God but You,” a formula that excludes any second deity 1 Chronicles 17:20.

A parallel royal prayer likewise says, “There is none like You and there is no other God but You,” reinforcing exclusive monotheism 2 Samuel 7:22.

Prophetic hope looks to a universal acknowledgment of that oneness: “GOD shall be sovereign over all the earth; in that day there shall be one GOD with one name,” envisioning God’s sole worship everywhere Zechariah 14:9.

Early Christian confession, articulated by Paul, affirms divine uniqueness: “to us there is but one God, the Father, of whom are all things, and we in him,” which asserts one ultimate source of all reality 1 Corinthians 8:6.

In the same breath, Paul confesses “and one Lord Jesus Christ, by whom are all things, and we by him,” pairing the lordship of Jesus with the oneness of God while maintaining monotheism in Christian worship and theology 1 Corinthians 8:6.

This formulation situates Christian belief in one God within a strict affirmation of God’s sole creatorship and our life in Him, even as it names Jesus’ unique mediating role “by whom are all things” 1 Corinthians 8:6.

The Qur’an states unambiguously: “your god is one God; there is no deity [worthy of worship] except Him,” grounding Islamic faith in absolute divine oneness (tawḥīd) Quran 2:163.

It also records opponents’ objection—“Has he made the gods [only] one God?”—highlighting the Qur’an’s polemical insistence on exclusive monotheism against polytheistic surroundings Quran 38:5.

Further, “Your god is only Allah, except for whom there is no deity. He has encompassed all things in knowledge,” asserting both exclusivity and God’s comprehensive knowledge as aspects of His unique divinity Quran 20:98.