Published on June 28, 2021 by Eugene Ho

Baker Books, 2021 | 368 pages

A Book Review from Books At a Glance

By Ryan McGraw


Contrary to what some might think, not all books on a topic are the same. Some people are tempted to think that if you have read one book on the Trinity then you have read them all. Yet books do different things. Fred Sanders (and here) and Scott Swain aim to present a catholic and biblical Trinitarian theology in more expansive and condensed formats, respectively, emphasizing different key aspects of the doctrine. Robert Letham includes more Old Testament material and historical development than these other authors do, while Michael Reeves pursues a devotional approach that expounds the gospel.

Matthew Barrett presents the Trinity that he almost lost (45) and explains why many evangelicals today face the same danger. Defending classic Christian Trinitarian theology, with an eye to modern errors that have come to predominate evangelical churches, he shows how modern social programs have hijacked classic Trinitarian doctrine. This book is easy yet profound reading that will help believers understand classic Trinitarian theology, where the modern church is drifting away, and how to steer the ship back on course. It is a bold, clear, and invaluable guide to recovering and treasuring what is arguably the central doctrine of the Christian faith.

Barrett divides his book generally into asking how we have drifted away from classic Trinitarian theology, and how we can find our way home again. His premise is that a Trinitarian drift has occurred, in which the church moved from seeing the Trinity as basically irrelevant, to reviving interest in the Trinity by manipulating the doctrine to support social agendas such as gender, sexuality, class struggle, and other examples. The first three chapters show that such a drift is a present feature in evangelical churches, the different model provided by the early church, and a narrative of how social agendas changed the church’s approach to the Trinity. Particularly, he targets the “New Calvinist” movement, including notable authors such as Wayne Grudem and Bruce Ware. He concludes that their defense of the eternal functional subordination of the Son in order to bolster equal being yet distinct roles among men and women does not mark a Trinitarian renaissance or revival, but a departure from orthodoxy.

Stating the matter boldly, he writes, “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” (92). I will illustrate below why this note is so important and that the stakes are high in relation to modern evangelical modifications of, and even defections from, classic expressions of the Trinity.

Chapters 4-8 represent Barrett’s positive case for understanding and returning to orthodox trinitarian teaching. His style is imaginative and interesting, often introducing chapters with fictional dialogues to get readers into his material more easily. For instance, his fictional account of a first-century believer name Zipporah coming to faith in Christ (beginning in chapter 4) is particularly illuminating (98-104). Using this character as a paradigm, he shows the gradual and natural way in which a first-century Christian would have gradually understood God’s triunity. This is an instructive and believable depiction of how the centrality of the Trinity in the New Testament Scriptures emerged as the events surrounding Christ’s life, death, resurrection, ascension, and outpouring of the Spirit could dawn on believers as events unfolded. Pulling this useful literary device into other chapters, Barrett helps readers see God’s Triunity in an unfolding story, making his narrative both gripping and theologically mature.

Chapter 5 is particularly valuable in that it defends divine simplicity (God is his attribute) while showing the necessity of this attribute for the Trinity. The Son and the Spirit must be all that God is in order to be God at all. Differing only in their eternal relations of origin, the divine persons are truly and fully divine in every sense of the term (150). This point is important because simplicity has fallen on hard times in modern theology. Barrett illustrates that it is no accident that traditional conceptions of the Trinity have fallen on hard times simultaneously. Moreover, social trinitarian models have shifted the goal lines by redefining personhood in God from relations of origin (see below) to social relationships. This reviewer believes that this redefinition of terms is part of the unspoken crux of the matter in modern debates among evangelicals.

However, chapters 6-7 press home the key issue at the present time and the target of the book through the lens of eternal generation. While many modern authors either reject or modify eternal generation, Barrett rightly presents the doctrine as a question of an eternal relation of origin. This means that eternal generation describes the sense in which the Son is God: he is God of the Father. In other words, the Son is God by eternal communication of the divine essence from the Father. This is what it means to be the second person of the Trinity (and so with the Spirit). Some modern Trinitarian theology has replaced the idea of eternal relation of origin with authority and submission. Though Barrett does not draw much attention to the fact, even John Calvin shifted away from historic Trinitarian theology by relegating eternal generation to the Son’s personhood, excluding his essence. This was an unthinkable move in light of the history of Christian doctrine, since the three persons are the single divine essence, and eternal relations of origin described the personal subsistence in that divine essence by the Son and the Spirit.

Failing to distinguish personhood from essence in God destroys the Trinity, but separating personhood from essence in eternal generation treats the divine nature as a fourth thing that all three persons share without remembering that the persons generated and spirated are divine persons. Few realize the implications of this point. In particular, functional subordination views jettison divine equality in irreversible order by redefining the terms of Trinitarian theology completely. Going beyond these fundamental points, Barrett examines “nine marks of an unhealthy generation,” which threaten the Son’s equality with the Father and personal distinction from him (156; listed on pg. 166). While chapter 6 defends eternal generation, chapter 7 illustrates why the doctrine is necessary to the gospel. Both of these chapters are masterful and wonderfully clear in their defense of orthodox Christianity. At the very least, readers will be compelled to conclude that modern trinitarian views that teach functional subordination are not the views of the historic Christian church (or, more importantly, the Bible).

Chapter 8 tackles modern debates over the eternal subordination of the Son to the Father even more directly and forcefully. Stating his case boldly, Barrett writes, “it’s time to sober up: EFS undermines biblical orthodoxy and threatens to sink evangelicalism in the swamp of social trinitarianism. In a word, EFS is novel” (225). Following careful analysis and devastating critiques of EFS, he concludes rightly, “After two thousand years of robust credal accountability, we should feel uneasy and suspicious whenever someone advocates a position on the Trinity that is novel. The burden of proof is on them, not us, to show otherwise” (257). This statement sets the right tone for modern discussions on the Trinity. We rest our faith on the teaching of the Bible alone, but Scripture also demands that we believe that Christ has been faithful in using the church to interpret the Bible. Is not the church and her officers the means by which Christ promised to prevent us from being tossed about by every wind of doctrine and to bring us to unity and maturity in Christ (Eph. 4:11-16)?

As Barrett notes earlier in the book, every heretic has a Bible verse (35). While the church is not infallible, only Scripture is, believers read the Bible best and most profitably by drawing from the most clearly established biblical doctrines of the church. We often act like teenagers, coming into adulthood and assuming that they know more than their parents, when the parents may actually have something useful to teach them. Instead of quoting Scripture and rejecting what our forefathers wrote about the Bible, we should seek to find out why they said what they did. Since most readers won’t be able to investigate historical theology in-depth, books like this one can help expose them to important classic ideas.

Chapters 9-10 wrap up the author’s treatment of the Trinity by stressing the third person of the Trinity and the unified works of the divine persons as well as why the Bible places appropriate stress on one person in many things God does and says. In particular, his defense of the Augustinian idea of the Spirit as a gift (276-279) is particularly useful for explaining why the Spirit does what he does in creation and especially salvation. While many other high points stand out in this book, the survey above illustrates why it is relevant and why I believe that he proves his case. Though he is bold in his conclusions, he is on the right side of history and biblical interpretation, and his voice needs to be heard in the present day.

Simply Trinity is simply a good book. While many medieval and post-Reformation developments are missing, Barrett meets us where we are today, giving us enough historical and biblical material to raise questions that need asking. His work may even make many uncomfortable, but in a good way. Becoming too comfortable with how things are, we may never know to ask how they should be. If you know anything about modern Trinitarian debates or have vague questions about them, then you won’t likely be able to put this book down.


Ryan M. McGraw

Greenville Presbyterian Theological Seminary

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Baker Books, 2021 | 368 pages

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