Looking for a not-so-technical book which explains the doctrine of the Trinity? Matthew Barrett’s Simply Trinity: The Unmanipulated Father, Son, and Spirit would be a good place to start.
Exactly 1700 years ago this year, back in 325, a gathering of Christian leaders at the modern lake-side city of Iznik, Turkey began a process which took almost a century for the brightest minds in Christendom to hammer out the basic idea of the Triune nature of God. Even still, what the Nicene Creed summarizes regarding the doctrine of God has generated volumes of theological works down through the ages. Millions of Christians (though not all!) recite the core features of the Trinity expressed in the Nicene Creed every week during worship services. But once you go beyond the idea of “One God in Three Persons”, it can be intimidating to try to think through what it all means.
The doctrine of the Trinity is one of the most central doctrines of the Christian faith, but it is also one of the hardest theological concepts to grasp without falling off the edge into heresy. As a young Christian myself, I early on adopted the analogy of water to explain the Trinity: one substance with three distinct states: a gas like steam, a liquid like water, and a solid like ice. It sure made sense to me back then. Little did I know that such an easy formulation is regarded as a heresy by some of the most brilliant theologians in the church.
Ouch.
While some authors, like the 5th century African Saint Augustine of Hippo, have written classic works on the Trinity, others have distorted the doctrine or rejected it as unimportant. The father of 19th century Protestant liberalism, Frederick Schleiermacher, pretty much dismissed the doctrine of the Trinity as a metaphysical waste to be easily disposed of. In response, more than any other theologian of the 20th century, the Swiss thinker Karl Barth recovered the doctrine of the Trinity as part of the core teaching of Christianity, rescuing it from Schleiermacher’s attempts to discard it. Conservative evangelical theologians since then have taken a renewed interest in articulating this doctrine of God for the postmodern era. Some get it right, but according to Matthew Barrett, a professor at Midwestern Baptist Theological Seminary, some have gotten it terribly wrong.

Simply Trinity: The Unmanipulated Father, Son, and Spirit. Baptist scholar Matthew Barrett wants to revive the classic doctrine of the Trinity, keeping the doctrine of God unmanipulated by contemporary social concerns.
Recovering the Classic Doctrine of the Trinity
In Simply Trinity: The Unmanipulated Father, Son, and Spirit, Matthew Barrett is concerned that even in some of our best evangelical seminaries that many have fallen into a kind of “trinity drift,” whereby Christian thinkers have ever so increasingly veered away from the classic formulation of the Triune doctrine of God, as articulated in the famous Nicene Creed. While some of the terminology and names associated with the great 4th century debate over the Father, the Son, and the Holy Spirit will be unfamiliar to some, Matthew Barrett wants to make the doctrine of the Trinity accessible to interested lay persons who do not know who either Arius or Athanasius was.
Oddly enough for a serious book on theology, Simply Trinity is actually a fun read. Barrett tosses out enough pop culture references to engage his audience, mainly ordinary Christians who want some type of fairly easy read to try to make sense of a complex doctrinal topic. Simply Trinity is not only educational, it is entertaining, listening to it in Audible audiobook form.
Harkening back to the movie classic, Back to the Future, Barrett invites the reader regularly to go “back to the DeLorean,” to meet some of the figures in church history who wrestled with terms like “essence” and “person,” when we think about the Father, the Son, and the Holy Spirit. Barrett apparently loves basketball, so he envisions a kind of “Dream Team” to champion the cause of Nicene Orthodoxy. The NBA has had its Magic Johnson and Larry Bird, but the church has had its Athanasius and Thomas Aquinas. Did you know that the Puritan theologian John Gill was the “Patrick Ewing” of trinitarian authors, or that Augustine of Hippo was the “Michael Jordan” of the early church? It is a clever way for Barrett to introduce some deep ideas. I think it works.
In Simply Trinity, Barrett, the host of the Credo Magazine podcast, wants to argue that what makes the doctrine of the Trinity so beautiful and essential to faith is its simplicity. In summary, the Father is unbegotten, the Son is begotten, or generated from the Father, and the Spirit is spirated, or breathed out, from the Father. These qualities have to deal with the internal character of the persons in terms of their origins, often called the “immanent” Trinity. God also acts in history, which displays his external relations to the creation, what is often called the “economic” Trinity. The “immanent” Trinity is about who God is, whereas the “economic” Trinity is about what God does.
Yet as Barrett sees it, the problem with a lot of modern understandings of the Trinity is that ideas have been invented by theologians regarding the “economic” Trinity, and that these ideas have been imported back into the “immanent” Trinity, thereby causing distortions as to who God really is.
“To be blunt, they have not revived the Trinity, but they have killed it, only to replace it with a different Trinity altogether – a social Trinity – one that can be molded, even manipulated, to fit society’s soapbox” (Barrett, 92).
Barrett is bothered by what he understands to be conceptions of a “social doctrine of Trinity,” emphasizing what God does, as a model for human interpersonal relationships, whether these be principles for governance and politics, economic structures, the organization of the church, and how Christians should think of marriage and family.
Jürgen Moltmann, the great German Reformed theologian of the late 20th century, though not fully a conservative evangelical, pioneered the concept of a “social trinity.” Moltmann developed this theology in an effort to provide a Christian basis for relations within society, and other causes, ranging from care for the environment to a critique of economic systems, like capitalism. Theologians, both liberal and conservative, have followed Moltmann in his wake to apply the model of “social trinity” to other areas of human communal life.
To make his case against a “social trinity,” Barrett sufficiently rehearses the history of the Nicene controversy of the 4th century, and how some of the best theologians since then have reaffirmed the truth of the classic Nicene doctrine of the Trinity. Names like Arius and Athanasius emerge, helping to form the narrative for this ancient theological battle of ideas. Along the way, Barrett illustrates his points through a fictive admirer of Jesus, a Jewish woman named Zipporah, who narrates her own encounter with Jesus and the religious leaders who opposed him. It is a pretty creative way to educate people about the classic doctrine of the Trinity, without diving too much into sophisticated theological jargon.
However, the zinger comes when Barrett attacks the efforts of “social trinitarian” scholars who inadvertently distort the classic doctrine of the Trinity. He chides evangelical egalitarian scholars who base the relations within marriage, between husband and wife, on the supposedly social arrangement within the Triune persons in the Godhead. A husband and wife are essentially equal in their relations to one another because the social trinitarian theologian says that this mirrors the essential equality between the persons of the Godhead. But this is all wrong, says Barrett, because this way of talking about God is really a manipulation of the doctrine of God to serve a kind of social arrangement within human communities. Keep it simple, says Barrett, in response. Do not distort our understanding of God by introducing elements within trinitarian thought that no one before the modern era ever considered.
The Eternal Functional Subordination of the Son (EFS) as an Unhelpful Modern Theological Innovation
But Matthew Barrett saves his most stinging critique to take down the modern concept of the Eternal Functional Subordination (EFS) of the Son, advanced by scholars like Bruce Ware and Wayne Grudem (chapter 8). In the EFS view, God is ultimately defined in terms of a pattern of authority and submission within the Godhead. For example, the Father is in authority and the Son is in submission to the Father. Why is this important? Because it explains the earthly human pattern as to how a wife is to submit to the authority of her husband.
Classically understood, when the Son became incarnate as Jesus the Messiah, the Son was indeed submissive to the authority of his Father. This activity of God through the incarnation is about what God has done, but the EFS theologians have projected this functional arrangement of the Father in authority and the Son in submission back into the very immanent, ontological aspect of God in all eternity. The EFS theologians maintain that such an arrangement is gladly accepted by both the Father and the Son, therefore there is a kind of equality within God, so it has the appearance of orthodoxy. But Barrett makes the case that the EFS view ultimately veers away from the classic doctrine of God by projecting something from the economic activity of God towards humanity back into God’s very internal relations, a violation of Christian truth which has been received down through the ages.
What really shocked me was to learn about the EFS tendency to suggest that each person of the Trinity has a will of their own (chapter 10). For when one speaks of an eternal function of subordination of the Son to the Father, it implies that the Son has a will distinct from the Father’s will, with the same idea applying to the Spirit. This does border on tritheism, as the early church fathers aligned with Nicaea argued for the singularity of the divine will, and not three distinct wills.
What makes Matthew Barrett’s critique so striking is that Barrett acknowledges that he is fully committed to a complementarian view of marriage and church office, namely that the husband is the head of the wife, and that only qualified men are to serve as elders of a local church. But Barrett is fully convinced that what EFS theologians have done is to try to bolster their particular brand of complementarian theology by wrongly drawing on a false view of the Trinity, in order to support their views.
Regarding his criticism of the Eternal Functional Subordination of the Son (EFS), Matthew Barrett makes a most compelling case that EFS is off-the-mark. Back in 2016, evangelical Twitter exploded in controversy when another complementarian Bible scholar raised the spectre of EFS as being “heresy,” which generated hundreds and hundreds of comments online back and forth. Now that the air has cooled down several years later, in 2021 Matthew Barrett has written a very careful, sober case for why EFS, despite whatever good intentions it may have had initially, is simply barking up the wrong tree. Is EFS heresy? Well, if it is not, it sure leans in a direction away from the received tradition of the church, and we need a course correction, if we are going to have a fully robust, and simpler view of the Trinity as Matthew Barrett proposes.
Other reviews of the book are mostly very positive. However, defenders of EFS will probably say that Matthew Barrett has straw-manned their position, and misrepresented what they are trying to say. Perhaps this is the case, but I am not so sure. It is quite telling that such a committed complementarian thinker regarding marriage and local church elders would argue so strongly against the EFS view. One reviewer even acknowledges that Matthew Barrett once held to an EFS-like view, though Simply Trinity makes the case that he has now repented of that wrong viewpoint. So, I find it hard to believe that Barrett would so badly mischaracterize the weakness of the EFS position, if he indeed once held it himself.
On the other side of the gender debate, egalitarian critics of Matthew Barrett’s position argue that a complementarian view of male/female relations collapses without the EFS doctrine of the Trinity. But this alternative view does not hold up very well. An egalitarian must still find an explanation for passages like 1 Corinthians 11:2-16 and 1 Timothy 2:8-3:15, which are difficult passages that simply can not be easily waved away. Long before EFS became fashionable in evangelical circles, Christians have historically held to some kind of complementarian view of gender relations, between male and female. The fact that many complementarian scholars agree with Matthew Barrett testifies to the fact that complementarian theology is not tied to the hip of an EFS doctrine of the Trinity.
The strongest takeaway for me is in Barrett’s critique as to how advocates of EFS misuse 1 Corinthians 11:3, their primary New Testament prooftext, to defend the Son’s eternal functional subordination to the Father:
…when Paul says the “head of a wife is her husband, and the head of Christ is God” (11:3), he has in view the incarnate, suffering servant, who fulfilled his mission by means of his obedient life, death, and resurrection as the Messiah (Christ). There is absolutely nothing in the immediate or wider context that says anything at all about the Son apart from creation and salvation within the immanent Trinity. To infuse and impose discussions of immanent Trinity on this text is a failure to treat the context with integrity. Paul has in view the salvific lordship of the anointed One, the Messiah (Barrett, chapter 8).
For if the EFS advocates were correct, Paul would have said that the head of the Son is the Father, and not what he did say, “the head of Christ is God.” Paul intentionally speaks of the Son’s incarnate ministry as the Messiah, and not the internal relations between the Son and the Father. Without 1 Corinthians 11:3, the support for the EFS view basically falls apart.
Critical Engagement with Matthew Barrett’s Book on the Trinity
The book is not perfect, as there are a few places in Simply Trinity that left me twitching a bit. In chapter 10, Barrett flies his Reformed tradition colors rather proudly with his reference to the “doctrines of grace” embodied in the “five points of Calvinism.” That right there is enough to send non-Calvinist Christians into fits. But what was so odd is that I really did not get how Barrett’s appeal to the “doctrines of grace” really tied into the substance of his argument regarding the inseparability of the persons of the Trinity. Barrett could have just as easily made his point without annoying his non-Calvinist readers.
In his chapter 9 on the “spiration” of the Spirit (which in most versions of the Nicene Creed is called the “procession” of the Spirit), Barrett has a sidebar discussing the vexing issue of the filioque. In 589 C.E., about two hundred years after the Nicene Creed was finally formalized, the Council of Toledo in the West modified the Nicene Creed to say that the Spirit “proceeds from the Father and the Son.” That last phrase, “and the Son” is filioque in Latin. Originally, the Creed as agreed upon by both East and West simply read that the Spirit “proceeds from the Father.”
The insertion of the filioque has been regarded as heresy by the Eastern church ever since the Great Schism of 1054 C.E., as it unilaterally changed the Creed without the full participation of the East. Most Christians in the West are completely oblivious to this controversy. But if you ask an Eastern Orthodox Christian, who converses with Western Christians, the filioque controversy stands out as a real sore point. I think our Eastern Christian friends are right to register their protest.
Oddly, Barrett justifies the action of the Council of Toledo, appealing to Anselm’s reasoning that the addition of the filioque protects against any slippage of the church back into the heresy of Arianism, which compromises the fully divine nature of all three persons in the Godhead. But this justification seems like a contradiction of the main thesis Barrett is advancing in the Simply Trinity, that we should not be monkeying with the doctrine of the Trinity that was originally formulated in the 4th century by the early church fathers. For if you are going to be consistent and poke holes at modern innovations like EFS, you should also poke holes at earlier post-Nicene innovations from the 6th century, like the filioque.
Barrett criticizes modern translations, which the older KJV translated as “only begotten,” now as simply “only,” as John 3:16′s “For God so loved the world he gave is only Son.” But one need not drop the concept of God the Father “begetting” the Son because the Greek word monogenes is translated in a less interpretive manner in today’s translations. Later in chapter 7, Matthew Barrett does come back to acknowledge this: The idea that Jesus is God’s “only begotten Son” can be inferred from this and other passages. It is sufficient to ground the language of the Son’s “only begotten-ness” in other concepts aside from the contested analysis of the Greek word monogenes.
These criticisms aside, my takeaway is that Simply Trinity has changed my mind in a more general way. Back in the 1990s, I held to an egalitarian view of marriage and church structure with respect to elders, and I largely based it on the kind of “Social Trinitarian” theology being advanced back then in evangelical egalitarian circles. But Matthew Barrett has convinced me that whether promoted by egalitarian scholars or by complementarian scholars, trying to use the Trinity as a model for how to conceptualize male-female relations in either marriage or the local church is a wrong-headed way of thinking, in that it invariably leads to a distorted way of thinking about God.
More generally, Matthew Barrett as an evangelical Protestant makes a strong appeal to the “Great Tradition,” the confluence of thought found in Protestant, Roman Catholic, and Eastern Orthodox traditions, which can be traced back to the Council of Nicaea. He laments that a number of evangelical scholars in the name of what Barrett calls a ‘narrow, crude biblicism” have jettisoned the Great Tradition’s formulation of the Trinity in favor of something novel. This is refreshing, as in my mind, too many evangelical Protestants have confused their understanding of sola scriptura; that is, scripture and scripture alone as the final authority for matters of Christian faith and practice, with a kind of “nuda scriptura“; that is, scripture naked, whereby the Bible is stripped of certain understandings of tradition which have served the church well going back to the era of the early church fathers.
This is not to say that the patristic tradition, associated with early Christian luminaries like Saint Augustine and Ireneaus are infallible. Historically orthodox Christian faith was formed within the crucible of the early church. However, it is to say that if you feel compelled to ditch a traditionally received interpretation of the Scripture going back to the era of the early church, the evidence in favor of a revised view should be able to pass a high bar for acceptance. In the case of social Trinitarian models of theology, whether that be EFS or even egalitarian interpretations which Barrett critiques, those revisionist solutions have not met that high bar standard. Matthew Barrett has convincingly shown that novel concepts, such as the Eternal Functional Subordination of the Son, have set the bar far too low, thereby compromising the integrity of the Great Tradition. In effect, theological positions like EFS have managed to tweak the doctrine of the Trinity to serve purposes that were never envisioned by the 4th century architects of Nicaea who hammered out the classic doctrine of the Trinity.
Even if you lay the controversial chapter 8 aside, there is much in the other chapters of Simply Trinity that can help any Christian have a more confident view about the doctrine of the Trinity. A Christianity Today magazine review hails Simply Trinity with this: “For anyone who has read confusing blog posts about the Trinity in recent years, the book will help you regain your theological bearings.” Each chapter has helpful key point summaries, to keep the reader from getting lost, and interesting sidebars contain juicy nuggets, which helps to retain the reader’s focus. From even a purely devotional perspective, Simply Trinity is just a joy to read. The book captured my attention from beginning to end. I wish all theology books read like this one!!
As 2025 is the 1700th anniversary of the Council of Nicaea (or “Nicea,” as some spell it), look for a few more blog posts commemorating this all important date in Christian history.
The folks at Remnant Radio have a good interview with Matthew Bates about Simply Trinity. Enjoy!


