The Four Positions

What they believe

There is one God who eternally exists as three co-equal, co-eternal persons — Father, Son, and Holy Spirit — sharing one divine essence. Jesus is not a lesser divine being or an exalted human; he is fully God in the same way the Father is fully God. The distinction is relational (the persons are distinct), not ontological (they share the same being). The Son did not come into existence at any point — he is eternally begotten, not made.

Each component of this belief statement has been debated. For more information, see the Stanford Encyclopedia of Philosophy article on the Trinity. For definitions of key theological terms used on this page, see the glossary.

Varieties of Trinitarian thought

While all Trinitarians affirm one God in three persons, how they explain this has varied considerably. The main families of Trinitarian theology include:

These differences are not merely academic. Whether you start from the unity (Latin) or the persons (Eastern/Social) shapes how you read passages about the Father-Son relationship, how you understand subordination language, and what you consider the "problem" that Trinitarian theology is solving. For more, see How Trinitarian Arguments Have Changed.

Historical roots

Trinitarians see the theological development from the apostolic period to Nicaea as the church progressively articulating a truth that was implicit in the earliest Christian worship and proclamation. The worship of Jesus alongside the Father, the application of divine titles and functions to Christ, and the inclusion of Jesus within Jewish monotheistic devotion all pointed toward the formal articulation at Nicaea. While the concept of a triune Godhead with three co-equal, co-eternal persons (as stated in the section above) was not discussed until closer to the mid-fourth century, trinitarian historians tend to interpret the councils of Nicaea in 325 AD, Constantinople in 381 AD, and Chalcedon in 451 AD as not inventing a new doctrine, but giving more precise language to what Christians had believed and practised from the beginning.

The substantive declaration of the Council of Nicaea in 325 AD was that the Son was "of one substance" (homoousios) with the Father. The Council of Constantinople in 381 AD officially extended personhood to the Holy Spirit. The 56 years between these councils were far from settled. Interestingly, Anti-Nicene positions dominated for much of this period, with the Nicene term homoousios repeatedly rejected, banned, or replaced at councils including Antioch (341), Sirmium (351, 357, 358), Arles (353), Milan (355), and the twin councils of Ariminum and Seleucia (359). At the high point of anti-Nicene dominance in 357, the "Blasphemy of Sirmium" explicitly banned the term homoousios and declared the Father greater than the Son. However, the Nicene position became dominant after 378, when Emperor Theodosius I made it imperial policy — threatening punishment and the removal of church status for dissenters, whom his edict branded "foolish madmen" and "heretics," even though non-Nicene Christians were still abundantly numerous, perhaps even a majority, across the Roman Empire — and commissioned the Council of Constantinople in 381 to ratify it. Trinitarians argue that the intervening councils were driven by imperial politics (especially Constantius II) and Arian manipulation, and that Constantinople 381 represented the church's genuine theological maturation, rather than a political settlement. The Nicene Creed remains the foundational statement for Catholic, Orthodox, and most Protestant churches. See The 4th-Century Councils for the full story.

The arguments used to articulate and defend the Trinity have developed over time. The pre-Nicene Logos theologians (Justin Martyr, Tertullian, Origen) used Platonist metaphors and maintained a subordinationist framework — arguably closer to what this site calls Logos Theology than to later Trinitarianism, since they all maintain that the Father is greater than the Son. Augustine (5th century) introduced psychological analogies — memory, understanding, and will as an image of the three persons. Richard of St. Victor (12th century) developed the "God is love, therefore Trinity" argument that remains popular today. Aquinas (13th century) recast the persons as "subsistent relations" in Aristotelian metaphysics. In the 20th century, Moltmann and others developed "Social Trinitarianism," presenting the three persons as a model community of mutual love. Trinitarians see each of these developments as legitimate theological deepening — the same core truth expressed with increasing precision. Others observe that the need to re-articulate the doctrine in new philosophical frameworks across the centuries raises questions about its relationship to the biblical text. See How Trinitarian Arguments Have Changed.

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What they believe

Biblical unitarians believe in the same God and Father of Jesus (John 20:28). They believe that the Father alone is the "only true God" of the Bible (John 17:3). They believe Jesus is the Messiah and Son of God — a human being uniquely conceived, chosen, anointed, and empowered by God, indwelt by the Spirit of God without measure, and then exalted to God's right hand after his death and resurrection. Jesus has been given all power and authority in heaven and on earth, and has been given the name above every name that at the name of Jesus all may bow… to the glory of God the Father. Jesus is not God himself, he is God's Son. Jesus is not a pre-existent divine being, he is a human being. Jesus is not the second person of a triune godhead, a concept that does not exist anywhere in Scripture. The title "Son of God" denotes a relationship of agency and obedience, not shared ontology. Jesus is Lord because God made him lord (Acts 2:36), not because he has always been God. Jesus was truly tempted, yet without sin. Jesus truly trusted in the one who could save him from death (Heb 5:7). Biblical unitarians believe that "There is one God (the Father), and one mediator between God and man, the man Jesus Christ, who gave himself as a ransom for all people." (1 Tim 2:5–6)

Historical roots

This view has deep roots in early Jewish Christianity, where Jesus was understood within the categories of Jewish messianic expectation — as a human figure anointed by God, not as God himself. Paul of Samosata, bishop of Antioch from 260 to 272, held that Jesus was a human being in whom God's Logos dwelt uniquely but who did not pre-exist as a divine person. He was condemned in 268, but the position never disappeared. Photinus of Sirmium held the same core view a century later. The contested history of the 4th century — in which anti-Nicene positions commanding majority support were overturned by imperial decree — is seen by BU scholars as evidence that the Trinity was a political settlement and later innovation, not an original Christian belief.

During the Reformation, Michael Servetus was burned at the stake in Geneva (1553) for denying the Trinity. Faustus Socinus and the Polish Brethren established a fully organised anti-Trinitarian church in Poland with its own academy, printing press, and catechism — the Racovian Catechism (1605), which declared that the Father alone is the one God of Israel and that Jesus of Nazareth is his only begotten Son. The Latin edition was provocatively dedicated to King James I of England. In 1658, the Polish Brethren were expelled from Poland on pain of death — not refuted, but banished.

In England, John Biddle was imprisoned repeatedly and his catechism burned by the common hangman (1654). Isaac Newton spent decades researching the Trinity and concluded it was a post-biblical corruption — but kept his views secret because open denial was a criminal offence under the Blasphemy Act of 1697. John Locke was privately a non-Trinitarian and at times was a proponent for distinctly Socinian views. John Milton privately rejected the Trinity. Joseph Priestley, the discoverer of oxygen, had his home and laboratory burned by a mob for his Unitarian convictions. Unitarians were not decriminalised in England until 1813. Biblical unitarians hold that Christians have always been promised to encounter persecution, but not that they would do the persecuting.

Today the tradition continues in Biblical Unitarianism, with growing scholarly engagement from defenders who argue that the earliest Christology, and that held by the NT authors themselves, was a Dynamic Monarchian Christology, and that the move to ontological divinity was a later development driven by Hellenistic philosophical categories. See The History of Unitarianism for the full story.

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What they believe

Jesus, as the Logos (Word), is genuinely divine — but derivatively so. He was produced by the Father before the creation of the world and served as God's agent in creating everything else. He is divine by nature (not merely a creature), but subordinate to the Father in origin, authority, and rank. The Father alone is the unoriginate God; the Son's divinity flows from the Father. This is sometimes described as a "two-stage" or "degrees of divinity" model — the Son is truly God, but not in the same unqualified sense as the Father.

Historical roots

This was the dominant Christological position among pre-Nicene Church Fathers. Justin Martyr (c. AD 150) described the Logos as a "second God" subordinate to the Father. Origen (c. AD 230) taught that the Son was eternally generated by the Father but was a distinct, subordinate divine being. Tertullian (c. AD 200) coined the term "Trinity" but held a subordinationist theology — he used the metaphor of sunlight proceeding from the sun, same substance but derived, and his framework is closer to what this site calls Logos Theology than to the co-equal model later defined at Nicaea. After the Council of Nicaea in AD 325, this view was largely superseded by the homoousios formula, which insisted on full equality rather than derived divinity. However, the resistance to Nicaea's homoousios among the homoiousian ("similar substance") party of the mid-4th century can be understood as an echo of the pre-Nicene Logos position — affirming genuine but subordinate divinity. Many scholars argue that the pre-Nicene Fathers' position was closer to homoiousian theology than to the full co-equality that Nicaea ultimately enforced. See The 4th-Century Councils for the full history.

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What they believe

Oneness theology argues that God is one divine person, not three eternal persons. "Father," "Son," and "Holy Spirit" are biblical distinctions, but distinctions of manifestation and redemptive role rather than distinct centers of divine personhood. Jesus is understood as the full revelation of the one God in flesh (John 14:9; Col 2:9). In this model, the Son-language is tied especially to incarnation and messianic mission, while divine identity remains numerically one.

Historical roots

Historically, this trajectory is connected to Modalistic Monarchianism (Noetus, Praxeas, Sabellius), which emphasized the absolute monarchy of the one God against any reading that seemed to divide deity. In modern form, it is represented most prominently in Oneness Pentecostal movements (especially from the early 20th-century Jesus-name revival onward). Modern Oneness writers often stress continuity with biblical monotheism while distinguishing themselves from simplistic caricatures of ancient Sabellianism.

Major contemporary exponents include David K. Bernard and other Oneness Pentecostal theologians, especially within UPCI-linked scholarship and catechesis.

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