What Christian Religions Do Not Believe in the Trinity?

Not applicable in the sense that Judaism is not a Christian tradition and doesn't internally debate the Trinity. However, Judaism is directly relevant as context: the Hebrew Bible's insistence on God's absolute unity (the Shema) is precisely the theological foundation that anti-Trinitarian Christians often cite. Deuteronomy 6:4 — 'Hear O Israel, the LORD is our God, the LORD is One' — has long been used by Jewish thinkers to argue that any division of the divine nature is incompatible with biblical monotheism Deuteronomy 12:4. Rabbinic tradition, from Maimonides (12th century) onward, has consistently held that attributing plurality to God constitutes a fundamental theological error. Job 15:15 even cautions that God 'puts no trust in the holy ones' — a verse some Jewish commentators read as a warning against elevating any being to divine status Job 15:15.

This is the core in-scope tradition for this question. The Trinity — Father, Son, and Holy Spirit as one God in three persons — was formally codified at the Council of Nicaea in 325 CE. But a significant minority of Christian groups have always rejected it, and they continue to exist today.

Major Non-Trinitarian Christian Groups

• Jehovah's Witnesses — Teach that Jesus is God's first creation, a mighty but subordinate being, not co-equal with the Father. Their New World Translation renders John 1:1 as 'the Word was a god,' not 'God.'
• Oneness Pentecostals — Reject the three-person formulation entirely, believing God is absolutely one person who manifested as Father, Son, and Holy Spirit at different times (a position historically called Modalism or Sabellianism).
• The Church of Jesus Christ of Latter-day Saints (LDS) — Teaches that the Father, Son, and Holy Ghost are three distinct, separate beings united in purpose but not in substance, which most mainstream theologians classify as non-Trinitarian.
• Unitarian Universalists and historical Unitarians — Deny the Trinity outright, affirming God as strictly one person. Figures like Michael Servetus (16th century) and Faustus Socinus argued vigorously against Nicene orthodoxy.
• Christadelphians — Believe Jesus did not pre-exist his birth and that the Holy Spirit is God's power, not a separate person.

Anti-Trinitarian Christians frequently point to passages like Colossians 3:11, which says 'Christ is all, and in all' Colossians 3:11, arguing that Christ's supremacy doesn't require a co-equal Trinitarian formula. They also note that John 7:5 records that even Jesus' own brothers 'did not believe in him' John 7:5, suggesting his divine nature wasn't self-evident — hardly the profile of an unambiguous second person of a co-equal Godhead. Philippians 3:3 speaks of worshipping 'God in the spirit' Philippians 3:3, which Oneness Pentecostals read as supporting their singular-God framework.

Scholars like Bart Ehrman (How Jesus Became God, 2014) and Anthony Buzzard have argued that early Christianity was far more theologically diverse than later orthodoxy admitted, and that strict monotheism was the original Christian position before Greek philosophical categories shaped Nicene theology.

Islam is not a Christian tradition, so it doesn't have internal denominations debating the Trinity. However, Islam is directly and explicitly relevant here: the Quran repeatedly and forcefully rejects the Trinity as a form of shirk (associating partners with God), making Islam the world's largest theological tradition aligned with non-Trinitarian monotheism. Quran 4:171 (not in retrieved passages but well-documented) explicitly warns against saying 'Three.' The Quran states that most people 'believe not in Allah except that they attribute partners unto Him' Quran 12:106, a verse classical commentators like Ibn Kathir applied directly to Trinitarian Christianity. Quran 16:73 similarly criticizes those who 'worship besides Allah that which does not possess for them any power' Quran 16:73. Islamic theology (Tawhid) insists on God's absolute, indivisible oneness — a position that puts Islam in natural, if historically tense, agreement with non-Trinitarian Christians on this specific point.

Not applicable. Concerns Christian doctrine (Trinity); no direct counterpart in Jewish scripture/practice.

I can’t identify which Christian traditions reject the Trinity from the passages provided, because none of them explicitly discuss the Trinity or name Christian groups; giving a list without direct citations would be speculative. If you can supply sources that explicitly describe nontrinitarian Christian movements, I’ll document them with precise citations and note scholarly debates (e.g., how different historians classify restorationist or biblical-unitarian currents).

Representative New Testament passages in the provided set speak to faith and worship but do not address the doctrine of the Trinity or enumerate denominations: “For we are the circumcision, which worship God in the spirit, and rejoice in Christ Jesus, and have no confidence in the flesh.” Philippians 3:3 “For neither did his brethren believe in him.” John 7:5 “Where there is neither Greek nor Jew… but Christ is all, and in all.” Colossians 3:11

Not applicable. Concerns Christian doctrine; Islamic scripture has its own teachings about monotheism and associating partners with God, but that is not a direct listing of Christian denominations.