4 Steps to Recognizing Bad Trinitarian Theology  

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Regarding the two “sides” in the fifth-century Christological controversies, R. V. Sellers observed,

So intent was each upon securing for itself the victory, that it would not stop to enquire whether its opponents did not after all believe what they said they believed.1

To find out what someone actually believes in order to engage with and critique it, one must do the courtesy of asking that person, not simply reading what those who disagree with them wrote. This is particularly true when it comes to those who reject the doctrine of the Trinity.

Non-Trinitarian religious groups

When I started to look closely at the arguments put forward by non-Trinitarians, particularly the writings of Christadelphians,2 I discovered that what was usually being argued against wasn’t orthodox Trinitarianism at all, but some parody or oversimplification of it, such as, “Trinitarians worship three Gods, not one.” Or, I found they were deconstructing a doctrine that is actually Apollinarian or Modalistic, rather than orthodox Nicene/Chalcedonian faith. Conversely, because non-Trinitarians are a minority of Bible-believers, and their publications can be difficult to obtain, their beliefs are difficult to research. Mutual misunderstanding leads both sides to more extreme positions—and on to mutual accusations of heresy. Trinitarians see non-Trinitarians as devaluing Christ and the Holy Spirit, while non-Trinitarians see Trinitarians as rejecting monotheism or denying the full and genuine humanity of Jesus. Yet I doubt that many members of non-orthodox groups ever consciously decided to become “heretics.” As with the diverse theologies of the past, they are trying to understand nothing less than what it means for there to be “one God the Father and one Lord Jesus Christ” (1 Cor 8:6).

Understanding what it means to be God

Now, ultimately, no one is truly going to understand what it means to “be God,” and we should not be so carried away with intellectual hubris as to assume that we do understand. Each of us is a created and therefore limited beings whose only life experience is as one finite person in one substance, fully human but not divine. The best we can hope to do, this side of seeing God face to face, is to understand and delineate the boundaries or “envelope” of truth, outside of which we stray into error.3 What are these boundaries? The vocabulary “three persons in one substance” needs to be understood as precluding:

  • Tritheism: belief in three separate Gods
  • Modalism: belief in one God who effectively changes hats or roles
  • Subordinationism: seeing the Son and Holy Spirit as less in “God-ness” than the Father

These errors we can recognize, and these “boundaries” help us to distinguish between true and false ideas.

Some Trinitarian Christians may misunderstand them, of course. If you’ve ever heard the Trinity “explained” by the analogy of water in the three forms of ice, liquid, and vapor, that’s actually Modalism. If you’ve heard the one about the three-leafed clover, that’s partialism, which says what we call God is the sum of three discrete persons.

Misunderstandings such as these fuel wrong ideas about God, but not only amongst mainstream Christians. And when non-Trinitarians hear them they rightly reject them—and may erroneously believe they are refuting “the Trinity.”

This article is an attempt to get behind the heretical doctrines of non-Trinitarian groups to what their advocates are trying to achieve. If we are to “speak the truth in love” (Eph 4:15), we must not impugn motives nor misrepresent others’ positions in order to triumph with our own arguments. Only if we first listen, read, discuss, and understand another point of view can we begin to address the heart of the matter. A battle of “prooftext ping pong” will not suffice. (And by the way, we don’t burn heretics anymore.) So, here is a suggested approach for engaging with non-Trinitarians from an informed perspective.

Engaging non-Trinitarians

Some non-Trinitarians undoubtedly reject the doctrine out of disbelief in the authority of Scripture.

Step 1: Christ

So, firstly, determine what the person or group’s perspective on Scripture is.

Rationalist Unitarianism

Rationalist Unitarianism4 stemmed from the Enlightenment and the exaltation of human reason above Scripture that underpinned much of liberal theology and some forms of “higher criticism.” This led to the deconstruction of the biblical accounts to remove the supernatural or “mythical” aspects of Scripture and press for a dichotomy between the historical Jesus of Nazareth, a moral teacher, and later Christology (allegedly) constructed by the church. A clear rejection of literal scriptural testimony is involved in any “Unitarian” or related belief that denies the virgin conception of Christ and regards Jesus as the natural son of both Joseph and Mary. It requires a metaphorical reading of Jesus’ Sonship or a rejection of the infancy narratives.

Modern Unitarianism, however, has such an eclectic meaning that each self-identifying Unitarian group must be considered in its own right.5 If the virgin conception, the incarnation, and other supernatural elements such as resurrection and miracles are rejected, the issue to focus on is Scripture as revelation, before any other doctrinal discussion can be fruitful.


One early group of heretical beliefs has been termed “Adoptionism,” a catch-all term for ideas that the man Jesus became Son of God or Christ at some point, or was specially endowed by God after his birth from Mary, usually his baptism.6 Any “divinity” of Jesus is therefore considered acquired, not natural. This may stem from scriptural or non-scriptural bases. Early “Adoptionist” ideas were based on ancient Greek dualist philosophies, which precluded any mixing of “divine” and “human.” Adoptionist tendencies may subtly influence or underlie beliefs that Christ has a derived, secondary, or lesser divinity—or is ultimately a creation of the Father.7 This way of thinking can develop even amongst Bible-believers.


A related idea, yet quite different from Adoptionism, is that the Son of God had no pre-existence before his conception as Jesus. This can still accommodate a virgin conception, and it is what Christadelphians believe. They locate Jesus’ Sonship in his miraculous conception (God, not Joseph, was his Father) but consider his Lordship to have begun at his exaltation.8

If a non-Trinitarian person or group accepts the infallibility and sufficiency of Scripture, they will believe that they hold the true scriptural teaching and that Trinitarians do not. They will be just as offended to be told that they deny “the truth” about God as an orthodox believer would be. They probably believe/have been taught that “the church” corrupted the original apostolic New Testament faith and has held to numerous non-biblical teachings and practices. They will not necessarily have much understanding of the details of all this, however, as they are unlikely to have formally studied church history. Unless you do have a sound knowledge of historical theology, it’s probably best to stick to talking about the Bible or to refer them to an appropriate resource. Suffice it to say that while the ancient church did argue—a lot—about the nature of the Godhead and the nature(s) of Christ, the foundational principles of one God and the divinity of Christ were held continuously from New Testament times.

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Step 2: The Father

The next step, once it is established that Scripture is their final authority, is to understand what your Bible-respecting anti-Trinitarian friend does believe. Do they consider “monotheism” to preclude any plurality within the Godhead? Most “biblical” non-Trinitarians begin with a genuine concern to uphold the one-ness of God (perceived as the Father alone) and the true humanity of Jesus Christ. Monotheism, the belief that there is only one “Divine Identity,”9 Godhead, or divinity, separate from his creation and the only proper focus of worship, is thought by non-Trinitarians to preclude more than one “person,” distinctive identity, or internal relationship within God. One writer distinguishes this from “Unitarianism” by the term “biblical monotheism”;10 however, orthodox Trinitarianism is also biblical and monotheistic, as opposed to being ditheistic, tritheistic, or polytheistic—terms mean nothing without agreed-upon definitions.


Trinitarian monotheism acknowledges plurality within the one Godhead, not external to him. The early church struggled to find the right vocabulary to conceptualize this truth. Just as today, misunderstandings about what one author meant by a particular word such as “being,” “substance,” or “person”—particularly when their respective semantic ranges did not overlap completely in translation between languages—led to the great controversies and church councils and creeds. Misdirected emphasis on the unity of the Godhead rather than the distinctiveness of Father, Son, and Holy Spirit led to Monarchianism, the doctrine of God as a single Monarch in the person of the Father. This could take the form of adoptionism or modalism (accompanied by the ice–water–steam or husband–father–employee analogies). Monarchianism blurred the distinction between the Father, Son, and Spirit, negating the biblical testimony to their distinctiveness and relational interactions. This doctrine led to the heresy that the Father died on the cross (“patripassianism”). Non-Trinitarians may mistakenly accuse orthodox Trinitarians of this error and present passages about the Son’s distinctiveness from the Father in refutation of Jesus “being God.”

Arianism and Socinianism

If a given person or group considers the Father alone to be the true God, with the Son and Spirit somehow derived from him, they will emphasize the distinctiveness of the persons and insist that the Trinity denies monotheism. Two historical examples include Arianism and Socinianism, approximated today by the Jehovah’s Witnesses (JWs) and Christadelphians, respectively.

Arianism was an attempt to preserve the Father’s role as the one divine Monarch by demoting the Son to the status of a created being.11 Arius of Alexandria (c. 250–336) taught that the Son had a derived form of divinity but could not be equal to the Father because the Godhead could not be divided. The Son, said Arius, was made by God at some undefined point before creation. This allowed for the “pre-existence” of Christ,12 making possible both his role in creation and his incarnation. It seemed to solve the “problem” of the relationship of the Son to the Father whilst preserving monotheism. What it didn’t do, in the views of its opponents, was do justice to baptism in the threefold name, the divine aspects of Christ, nor to his ability to truly redeem humanity.

Jehovah’s Witnesses

The JWs’ beliefs are not identical to Arianism, but their founder Charles Taze Russell considered Arius to have correctly refuted the Trinity. Russell saw the Council of Nicaea’s rejection of Arianism as the point of departure from apostolic teaching.13 JWs regard Jesus Christ as a created spiritual being in heaven prior to his coming to earth.14


Christadelphians are not Arian, nor are they Adoptionists; they are definitely not Unitarians. Their closest historical precedent may be the Socinian movement of the sixteenth and seventeenth centuries. Socinians rejected the doctrine of the Trinity as unscriptural and against reason; they defined God as an immutable heavenly being. Jesus, in their view, was born by the power of the Holy Spirit but did not pre-exist; and after his death he was raised and exalted to the right hand of God. Socinians believed that the Holy Spirit has no personal identity, but is merely the power of God.15 This is essentially the Christadelphian position; however, they differ from the Socinians in their understanding of the atonement.

Christadelphians, unlike JWs, reject any pre-existence of the Son before his conception in Mary. But in rejecting pre-existence, they are forced to interpret metaphorically every passage stating or alluding to that pre-existence. The Son existed only “in the mind of God,” who loved and glorified him in prospect. At the foundation of the Christadelphian view is a conflation of Christ’s foreordained work (which did not happen until his advent, they believe) and his eternal existence. This group also fails to fully account for God’s sending his Son and for Christ’s willing humiliation (see Phil 2:5–8).

These and similar viewpoints arguing that only the Father is God all ultimately derive from a simplistic understanding of monotheism, an unjustified fear of tritheism,16 and ultimately an acceptance of Subordinationism.


Subordinationism holds that the Son is inferior in being to the Father, not just in role. It can be found in nascent and speculative form in several early church writings, particularly those of Origen of Alexandria.17 Arius was doubtless drawing selectively on Origen to support his Subordinationist views.

Subordinationism is not to be confused with Subordination, which is part of the biblical and orthodox Christian understanding of the Son’s role in the incarnation and salvation. It may be helpful when engaging with these beliefs to discuss the roles, names, prerogatives, and deeds of God shared by Jesus. Is he “above the line” or “below the line” dividing divinity from creation?18 Talk about God sharing his glory with “no other,” (Isa 42:8; 48:11), yet sharing it with his Son (John 13:31–32; 17:1, 5, 24; 2 Cor 4:4–6; Heb 1:3; Rev 5:13). You could also explore what is meant by grouping Father, Son, and Holy Spirit together (e.g., in Matt 28:19; 2 Cor 13:14) and how Christ is presented as Creator (Col 1:15–17; Heb 1:3, 8, 10; John 1:1–3, 14).

Does the group or individual with whom you are interacting think that the doctrine of the Trinity precludes Jesus’ being truly human? If Jesus is “God,” what about the Bible’s testimony to his humanity? It may surprise them that orthodox Christian doctrine insists on the full and genuine humanity of Christ and his ability to experience our temptations. As Gregory of Nazianzus affirmed,

What has not been assumed cannot be restored; it is what is united with God that is saved. (Epistle 101.7)

Related article: Trinity or Triarchy? Is There Authority and Submission in the Godhead? by Michael Bird

Apollinarianism, Eutychianism, and Nestorianism

To argue that the divinity of the Son necessarily negates the humanity of Christ is to posit a false dichotomy and to misrepresent the incarnation. Early heresies which overwhelmed Christ’s humanity with his divinity (Apollinarianism and Eutychianism) were roundly rejected by the church. Likewise, any concept of Jesus Christ that sees his divinity as not fully integrated with his humanity (Nestorianism) is not authentic Trinitarian doctrine. It is also essential to recognize that the Son existed as God the Word throughout eternity (see John 3:13, 17:5; Col 1:16; Heb 1:1–3), but that the man Jesus of Nazareth had a distinct beginning at his conception/ incarnation when the Word became flesh and dwelt among us (see Matt 1:18; Luke 1:31–35; John 1:1–2, 14). Therefore, Jesus’ “being born” does not negate the Son’s pre-existence. Denial of Christ’s divine nature also requires that divine features, attributes, and actions attributed to him in Scripture must be either delegated or interpreted metaphorically (as Christadelphians do, for example). Alternatively, an Adoptionist perspective must be upheld.

Step 3: The Spirit

The next consideration is the person or group’s view of the Holy Spirit. Non-Trinitarian belief necessitates downgrading of the Holy Spirit from a person with full divinity to something else.19 Arius considered the Holy Spirit in similar terms to the Son, and early fathers such as Irenaeus and Origen considered the Word and the Spirit to be (eternally) derived from the Father, effectively the Father’s “hands” in his work with creation. In order to avoid the potential misunderstandings of the Father having two “Sons,” or of denying of the full divinity of the Spirit, theologians used the terms “procession” of the Spirit as distinct from “begettal” of the Son. Christadelphians consider the Holy Spirit an “it,” simply the “power of God.” By this “power,” God is everywhere present and acts in creation.20 This idea is typically accompanied by a denial of personal effects or “gifts” of the Spirit in believers today, apart from the effect of reading the Scriptures. (However, this idea is tenuous: Acts 13:2; Rom 8:9; 8:14–16, 26–27; 1 Cor 12:4–6; 2 Cor 13:14; Eph 4:30; 2 Tim 1:14; Tit 3:5.)

Depersonalizing the Spirit tends to result from or rely on a hermeneutic that prioritizes the Old Testament over the New, which also makes it easier to subordinate the Son. The Old Testament generally presents the Spirit of God in terms of God’s powerful effect on people at various places and times, equipping them for mighty acts in a transient and selective fashion. If this view of the Spirit is carried over to the New Testament, it contributes to a picture of the Spirit as an impersonal power. This viewpoint ignores the work of Jesus in revealing the Father (cf. John 14:7–9; 17:1, 3, 6, 8; 25–26) and inaugurating the age of the Spirit as the Other Comforter (cf. John 14:16–18, 26;16:7, 13–14; Acts 1:4, 8; 2:16–18, 33, 38–39). Does your non-Trinitarian friend think the Old or New Testament picture of the Spirit is the most detailed and complete?

Prioritizing of the Old Testament over the New also enslaves Christ to the shadows and types which he came to fulfill. The idea becomes, “His sacrifice was necessary because God requires sacrifice; his is simply better than bulls and goats.” Against this, orthodox Christianity maintains that Christ completes everything in the Law and Prophets because they always pointed to him; he is the culmination of everything written. Non-Trinitarians emphasize the subordination of the Son to the Father, not just in terms of the willing humbling and emptying of Philippians 2, but as the Son’s intrinsically inferior nature to the Father’s. The Son begins existence as a creature and is exalted because of his work. In contrast, Trinitarians believe that the Son was eternally with the Father and humbled himself in the incarnation, submitting himself in obedience unto death for our salvation. You will need to carefully tease out the passages that refer to Christ’s life on earth and his former and current status in heaven and distinguish between his essential being from his willingly undertaken role.21

Step 4: Atonement

This brings us to the final, important point. A correct understanding of the triune God is essential for a correct understanding of the atonement. Does your non-Trinitarian acquaintance reject penal substitutionary atonement? This tends to go hand-in-hand with a denial of the Son’s divinity and the complete initiative of God in salvation. If Christ is merely human (albeit divinely gifted), then the atonement becomes a result of human effort and was by no means guaranteed,22 and is a parody of justice. In this view of “substitution,” God chooses a perfectly innocent man to take the blame and punishment for other humans’ sins. So, in this view, Christ can never be more than our representative, which makes his power to save limited by our ability to imitate him. For the purely human Christ Jesus to have never sinned, the Spirit or some other influence of God must have absolutely dominated his human nature, which contradicts Scripture’s testimony—and he would cease to be truly representative of humanity. The representative-only model thus negates itself.

The more divine influence that has to be added to the human Christ in order for him to prevail, the further he moves from being solely human. But the less divinity we attribute to him, the greater the impossibility of him overcoming sin. It simply cannot work unless Christ is fully God and fully man, “to be acknowledged in two natures, inconfusedly, unchangeably, indivisibly, inseparably” (Chalcedonian Definition of 451). Also, denying the divinity of Christ denies the absolute sovereignty of God in the atonement, whereby God himself propitiated his own wrath, redeemed us, declared us righteous, and reconciled us to himself. The atonement is a work of God from beginning to end.23 Therefore, try to show how the atonement and Christ’s two natures (correctly understood) are linked. Use Isaiah 53 to show how Christ truly bore our sins and their punishment. Explain how a representative-only atonement is ultimately works-based salvation and robs God of sovereignty and initiative.


Respectful questioning (“How do you see Christ’s saving work as guaranteed?” versus, “Your Christ couldn’t save!”) can open up new avenues of thought and consideration of wider scriptural concepts and the consequences of a given belief. After all, the goal is to preach salvation in Christ, not to win an argument. There’s a lot at stake: “This is eternal life, that they know you the only true God, and Jesus Christ whom you have sent” (John 17:3).

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  1. R. V. Sellers, Two Ancient Christologies (London: SPCK, 1954), 203.
  2. Ruth Sutcliffe, The Trinity Hurdle: Engaging Christadelphians, Arians and Unitarians with the Gospel of the Triune God (Eugene, OR: Wipf & Stock, 2016). See also this blog piece.
  3. Roger Nicole, “The Meaning of the Trinity,” in One God in Trinity, ed. Peter Toon (Westchester IL: Cornerstone), 1980, 1–10, explains this well, with a helpful diagram showing how an imbalance of one aspect of Trinitarian doctrine makes orthodoxy resemble heresy.
  4. For the difference between “biblical” and “rational” anti-Trinitarianism, see Stephen R. Holmes, The Quest for the Trinity: The Doctrine of God in Scripture, History and Modernity (Downers Grove: InterVarsity Press, 2012), 170–180.
  5. A helpful overview of Unitarianism is I. Breward, “Unitarianism,” in New Dictionary of Theology, eds. Sinclair B. Ferguson and David F. Wright (Downers Grove, IL: InterVarsity Press, 1988), 700–701. In the USA, many Unitarians have merged with Universalists.
  6. However, as Peter-Ben Smit, The end of early Christian adoptionism?: a note on the invention of adoptionism, its sources, and its current demise,” International Journal of Philosophy and Theology 76:3 (2015): 177–199, argues, the term “Adoptionism” is more correctly applied to theories much later than the early church and tends to be retrospectively applied to early teachings. It should not be considered in too narrow a sense.
  7. For example, the Jehovah’s Witnesses.
  8. Based on a particular understanding of passages such as Acts 2:22, 36; 17:31; Rom 1:4. Christadelphians sometimes sound Adoptionist, but they fundamentally are not.
  9. This is Richard Bauckhams’ term, and I think it’s helpful. See Jesus and the God of Israel (Grand Rapids, MI: Eerdmans, 2008) for an excellent discussion of Trinitarian monotheism.
  10. Rob J. Hyndman, “Biblical Monotheism Today,” in One God, the Father, ed. Thomas E. Gaston (East Boldon: Willow, 2013), 225–40. Hyndman includes Christadelphians; the Church of God of the Abrahamic Faith; Church of God (General Conference); The Way International; Spirit and Truth Fellowship International; Living Hope International Ministries; and Christian Disciples Church under this heading, although these groups are diverse in their wider beliefs.
  11. Similarly the Holy Spirit, but the initial Arian controversy focused on the Son’s relationship to the Father.
  12. Although, infamously, insisting “there was [a time] when he was not.” The original Creed of Nicaea 325 anathematized this idea, as well as those of the Son coming into existence out of nothing, being of a different substance than God, being created or subject to change. For more on the doctrines of Arius, see Holmes, Quest for the Trinity, 82–92.
  13. Charles Taze Russell, Studies in the Scripture (Brooklyn International Bible Students Association, 1918). See also this article.
  14. See this article and this one.
  15. Szczucki, “Socinianism,” 85–86; Smith, “Truth in a Heresy?,” 221–24.
  16. I am not aware of any contemporary acceptance of tritheism; usually, it is what non-Trinitarians accuse Trinitarians of. The ancient Western church accused the Eastern church of tritheism because of their interest in the distinctiveness of the persons, whereas the Eastern church regarded the Westerners as effectively modalist.
  17. For example, in On First Principles, bk. 1, ch. 2.
  18. For refutation, see Robert M. Bowman Jr and J. Ed Komoszewski, Putting Jesus in His Place: The Case for the Deity of Christ (Grand Rapids, MI: Kregel, 2007).
  19. For a defense of the deity and personhood of the Holy Spirit, see Sinclair B. Ferguson, The Holy Spirit (Downers Grove: InterVarsity Press, 1996); Millard J. Erickson, Christian Theology, 3rd ed. (Grand Rapids, MI: Baker, 2013), 782–787; Sutcliffe, Trinity Hurdle, 166–186
  20. Robert Roberts, The Christadelphian Instructor, articles 16–18; Harry Tennant, The Christadelphians: What they Believe and Teach (Birmingham, AL: Christadelphian Bible Mission, 1998), 115.
  21. See Sutcliffe, Trinity Hurdle, 96–124.
  22. Christadelphians insist that Christ could have failed, and deny any explicit control or coercion by God. Tecwyn Morgan, Understand the Bible: Work It Out for Yourself (Birmingham, AL: Christadelphian Bible Mission, 2006), 109, 111
  23. For a magnificent account of this, see John Stott, The Cross of Christ (Leicester: InterVarsity Press, 1986), 235–36, and whole chapter.
Written by
Ruth Sutcliffe

Ruth Sutcliffe received a PhD in historical theology from the Australian College of Theology and serves Bible colleges in the Majority World. She is the author of 'The Trinity Hurdle: Engaging Christadelphians, Arians and Unitarians with the Gospel of the Triune God' (Wipf & Stock, 2016).

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