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Short Studies in Systematic Theology

The Trinity: An Introduction

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The Trinity is one of the most essential doctrines of the Christian faith.

The eternal God existing as three distinct persons - Father, Son, and Spirit - can be difficult to comprehend. While Christians often struggle to find the right words to describe this union, the Bible gives clarity concerning the triune God’s being and activity in nature (creation), grace (redemption), and glory (reward). In this concise volume, theologian Scott Swain examines the doctrine of the Trinity, presenting its biblical foundations, systematic-theological structure, and practical relevance for the church today.

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Published October 20, 2020

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About the author

Scott R. Swain

35 books44 followers
Dr. Scott R. Swain is President and James Woodrow Hassell Professor of Systematic Theology at Reformed Theological Seminary in Orlando, Florida. Dr. Swain has served on the RTS faculty since 2006, having previously taught at Southwestern Baptist Theological Seminary in Fort Worth, Texas.

His main research interests include the doctrine of God, theological interpretation of Scripture, and modern Protestant theology, and he has published a number of books and essays on these topics. With Dr. Michael Allen, he serves as general editor of two series: Zondervan Academic’s New Studies in Dogmatics and T & T Clark’s International Theological Commentary.

Dr. Swain is an ordained minister in the Presbyterian Church in America. He and his wife, Leigh, have four children.

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Displaying 1 - 30 of 209 reviews
Profile Image for Ronni Kurtz.
Author 6 books214 followers
February 21, 2022
Re-read this tonight trying to decide if I should make it required reading in my theology one undergrad courses. The verdict is yes. I was reminded how gifted Swain is at making the Biblical data come alive with such ease in Trinitarian discourse. Moreover, he pairs a theological reading of the text together well with using the pro-Nicene grammar and categories. This is the exact kind of text that undergrad students should spend some time with.
Profile Image for Lydia Bethay.
41 reviews
January 28, 2025
Read this book! Any book on the Trinity is going to make your brain hurt and will have you be like Michael Scott when he asks, “explain this to me like I’m 5”, but Swain does such a good job at being precise, clear, and accessible to his reader. Swain also did a great job leading his theology to doxology.

“The triune God alone is the ultimate end of all his works, the supreme benefit he gives, the supreme benefit that can be received. God the Father manifests his glory in God the Son and, through him, communicates his blessings in God the Spirit because the triune God alone is supremely worthy of showing, and supremely worthy of sharing with others. As this one thing, God the blessed Trinity, is the final end of all God’s ways and all God’s purposes, it should be the ‘one thing’ we seek as well,”
Profile Image for Jacob Moore.
135 reviews13 followers
January 18, 2023
Wonderful book! This and Michael Reeve's book Delighting in the Trinity are two wonderful resources that anyone in the church can access. This resource does a little more work than Reeves on helping us learn the "grammar" of God and how we speak of him, which will enrich our reading of Scripture and prayer lives immensely if attended to.

Almost every Christian should read a book like this as soon as possible!
Profile Image for Lisa.
272 reviews12 followers
June 23, 2025
***Best Theology Book of 2023***

I hardly have words to explain how profound and beautiful is our glorious Triune God. Read this book slowly, read the verses sited, and rejoice in and worship this great God.

“Here is treasure hidden in a field and the pearl of great price: knowing, receiving, loving, and praising the Father, through the Son, in the fellowship of the Spirit. To him be glory forever.” (p 23) Amen and amen!
Profile Image for Jacob Aitken.
1,682 reviews413 followers
April 1, 2025
Swain, Scott. The Trinity: An Introduction. Crossway, 2020.

I have long maintained that Matthew Barrett’s Simply Trinity is the best introduction to the Trinity. I still think that, but if one were to recommend Swain’s book as the best, I am not sure I would disagree. Writing in the aftermath of the Trinity War of 2016, Scott Swain reminds American Evangelicalism of what it is supposed to believe about the Trinity.

Some might object, “But are you not elevating Nicea over Scripture?” It is not that simple. One could say Nicea is simply restating Scripture. I believe that is true, but that begs the question against the biblicist. Fortunately, we have a better answer: the Trinity comes with its own grammar, a grammar biblicists do not have. Swain’s book explicates that grammar.

He begins with the three-personed Name into whom we are baptized. This Name is the one God, who we know as Father, Son, and Holy Spirit. Lest we fall into modalism, we identify these persons by their relations of origin, which Swain calls “relations of from-ness.” These are personal properties: the Father begets, the Son is begotten, and the Holy Spirit is spirated from Father and Son. Other properties, such as wisdom or eternality, are common to the essence.

He has a helpful chapter on simplicity. God is identical with his perfections, meaning there is no compound of parts. The only distinctions, then, are their relations of origin to one another. That should be enough to rule out most forms of social trinitarianism, but Swain takes it a step further: the persons of the Trinity are not species under a genus labeled “God.”

Making him somewhat unique among evangelical theologians, although that problem is slowly being remedied, Swain gives a short defense of the Filioque. The Holy Spirit’s “personal distinction lies in the way He has what He has.” The “what he has” is the divine essence. The way he has it is his mode of origin. His identity and agency point back to his relation of origin. But must He be from both Father and Son? Yes, for if He came only from the Father, he would share a personal property with the Son, that of “being-from-the-Father.” Therefore, His personal property is “being-from-both-Father-and-Son.”

Swain advances another line of argument: The Son receives the property of breathing forth the Spirit. I am unsure. It seems if we say that, the Son shares a personal property with the Father.

His best chapter is on missions and appropriations. A maxim in Trinitarian studies is the external acts of the Trinity are undivided. That said, the actions themselves follow a Trinitarian pattern. They are from the Father through the Son in the Holy Spirit. Nonetheless, some works manifest a person more specifically.

He has a beautiful section on missions. A Trinitarian mission terminates on creatures, the extension in time of a person’s relation of origin. Quoting John Webster, a mission has an eternal depth with a temporal shore. Gilles Emery notes they are “royal embassies of an eternal kingdom.”

Eternal Subordination

Swain has several sections against eternal subordination, but not as deep as one would expect. He notes that ESS/ERAS “fail to observe the distinction between acting and mode of acting.” I wish he would have expanded upon that.

Conclusion

Get this book. Buy it in bulk. Pass it out to your congregation.
7 reviews
January 14, 2025
I remember in one of the Austin Powers movies, where Powers tries to understand how time travel works. As He starts to talk through it, struggling with all his mental might, he says, "oh no! I've gone cross-eye." I had a similiar moments while reading Trinity: An Introduction. It's not that Swain was unclear or confusing; he wasn't. It was the great mystery of the triune God reveled in the pages of the Bible. Phrases and statements like, The second person of the Trinity is "Eternally Begotten" and God is "one Being distinguished in three persons." How is something "eternally Begotten"? Oh wait, I've gone cross-eyed.

Swain cleared my vision by grounding my thoughts in the basic grammar of how the Bible describes God. And as he walks through passage after passage, I came to appreciate, the terms of "Simplicity", "Origin of Relations", and "Person". The terms, although technical, reflect a desire from Christains, both past and present, to accurately describe who God is from the Bible. To give us a grammar to talk about the Trinity.

The book was a great reminder on how separate or Holy the triune God is, but we can know God in His Word--the Father, Son, and Spirit. "Learning to know the triune God, to receive the triune God, to rejoice in the trinune God--and learning to help other do the same--is an end in itself, because the triune God is the ultimate end of all things."
Profile Image for Kristina .
1,322 reviews74 followers
March 12, 2025
4.5 stars, rounded up

"While we cannot hope to comprehend the wonder of God's triune life, we can press more deeply into the Bible's Trinitarian discourse."

I've been wanting to learn more about the Trinity for quite some time, as it is one of the Biblical concepts that is elusive in both true understanding and explanation to others. This text leans academic, but is a great resource for delving deeper into the triune nature of God.

Format: Book, owned
Rating: 4.5 stars
Book 3 of 2025
Profile Image for Matt Pitts.
756 reviews74 followers
June 29, 2021
Simply superb. Easily the first book I would recommend on the doctrine of the trinity. Beautifully written with a simplicity and depth reminiscent of John's Gospel.
Profile Image for Brian Parks.
65 reviews8 followers
November 8, 2021
An excellent introduction written in a simple and clear style. Technical enough to push most lay level readers but simple enough for lay readers to understand.
Profile Image for Easton Tally.
41 reviews2 followers
January 6, 2024
3.5 stars - a great read for those interested in the topic, but surprisingly a tad redundant despite it’s short length.

While scripture teaches us of the Trinity and its complexities (and simplicities) through different types of texts (Inter-Trinitarian conversations, Cosmic Framework texts, and redemptive mission texts), what they all teach is his oneness yet distinctness in relation of origin (the Father begets the Son and the Father & the Son breathe forth the Spirit)… All confusing stuff at least to someone like me, but what slowly became more beautiful to me throughout this book is that all of His works toward creation and his beloved follow a Trinitarian shape - proceeding from the Father through the Son in the Spirit. Distinct, yet indivisible.

Perhaps even more glorious is that Trinitarianism has profound ramifications for eternity. . . “Homes are built for a reason. And this home is built for union and communion between the triune God and his beloved, redeemed children, for the marital bliss of Christ and his bride.” If the end of all creation is God himself, and God himself exists in perfect harmony and unity - He will surely bring us into it. How beautiful!
13 reviews
January 30, 2025
This was a great book, and I highly recommend it. Some points that stick out to me that I especially found helpful were his comments on eternal functional subordination, and his doxological approach to the study of the trinity.

A point of interest that I am still considering regards his calling EFS “serious error”. While I generally agree with this terminology, I find that different people mean different things when they say “serious error”. In recent times, I have heard pastors and theologian’s talk about separating churches and denominations over this issue. The scope of this book was not meant to dive into the denominational implications for this doctrine, but it’s something I would like to be considering and reading further into in the future.
Profile Image for Drew Norwood.
481 reviews26 followers
February 21, 2022
A top-notch, well-rounded introduction to the doctrine of the Trinity. Every chapter opens with some variation of "Christians praise. . . ", repeatedly keeping the end before us: "we were baptized into God's triune name so that we might learn to praise God's triune name." Without neglecting the rigor and precision needed for addressing the Trinity, Swain consistently channels our focus to the aim our theology and our praise: "Ultimately, our fluency as readers of Holy Scripture and our formation in Christian virtue are ordered to this supreme end, the triune God himself, who gives himself to us as our supreme good in the grace of our Lord Jesus Christ, the love of God the Father, and the fellowship of the Holy Spirit (2 Cor. 13:14)."

Swain makes the “biblical grammar” of the Trinity clear and accessible. He establishes the historical boundaries for Trinitarian orthodoxy, and he shows how the doctrine is appropriately confessed. Related to this, another strong aspect of the book is Swain's theological humility. He demonstrates the role of restraint in approaching reveled mysteries. For instance, in speaking of the the Father eternally begetting the Son: "The mystery of the Son's eternal begetting is one that mortal minds cannot fathom. Because it is divine begetting, it is an unreachable deep (Ps. 1445:3, Rom. 11:33). Nevertheless, because the mystery of the Son's eternal begetting is a reveled mystery, we can learn to follow the grammar of biblical discourse, we can learn to sing its tune, even if we cannot grasp the deeper laws of the music by which it operates." And, speaking more generally, "The reason for attending to the Bible's Trinitarian discourse, and for disciplining our minds and lips before the radiance of God's simple light, is not to explain God's triune life but to stand in awe of it, to adore it, and to embrace it as it unfolds itself to us in Scripture. . . while we cannot hope to comprehend the wonder of God's triune life, we can press more deeply into the Bible's Trinitarian discourse.”
Profile Image for Eddie Mercado.
215 reviews8 followers
August 28, 2023
A pithy primer on the doctrine of the Trinity. Swain does a very good job in distilling two thousand years of theological development, thus resulting in a book which makes much of the Father, Son, and Holy Spirit. His use of common and proper predication was helpful, and I very much appreciated his work on Divine Simplicity. His chapter refuting ancient and modern Trinitarian errors is insightful. This would be a good resource for small groups or adult Sunday school.

//2nd read through in August 2023.
Profile Image for George P..
560 reviews62 followers
January 7, 2021
The Trinity: An Introduction by Scott R. Swain is the second book in Crossway’s Short Studies in Systematic Theology series. The first was Graham A. Cole’s Faithful Theology: an Introduction. According to series editors, Cole himself and Oren R. Martin, “each volume (1) introduces the doctrine, (2) sets it in context, (3) develops it from Scripture, (4) draws the various threads together, and (5) brings it to bear on the Christian life.”

Unfortunately, The Trinity does not accomplish the first two items in the editors’ list. In my opinion, one cannot understand Trinitarianism, the Christian doctrine of God, without understanding its historical development and creedal/confessional definition. Swain justifies this in terms of space limitations: “The book’s limitations in space and focus mean that it will not give extensive attention to the doctrine’s historical development, polemical uses, or more sophisticated dogmatic elaborations.” Given that this text is explicitly introductory, Swain’s choice to skip those topics—not to mention his editors’ decision to allow it—is difficult to understand.

Fortunately, what The Trinity focuses on is very helpful. Swain focuses on “the basic grammar of scriptural Trinitarianism.” He writes: “If Scripture provides the primary discourse of Trinitarian doctrine, theology is that discipline concerned with understanding and communicating Scripture’s basic grammar so that Christians may become fluent, well-formed readers and speakers of scriptural teaching.” This approach is helpful because the doctrinal definition of Trinitarianism employs terms that are not found in Scripture, terms that clarify what Scripture means and demonstrate is internal coherence. One must understand the interplay of these texts—along with the worship patterns of the early church—in order to understand why Christian theologians employed philosophical terms to define the doctrine. Only by doing so could they show the meaning and coherence of those biblical texts.

Here is the book’s table of contents:

1. The Bible and the Trinity: The Basic Grammar
2. The Bible and the Trinity: Three Types of Texts
3. The Simplicity of God
4. God the Father
5. God the Son
6. God the Holy Spiriti
7. The Shape of God’s Triune Work
8. The End of God’s Triune Work

Although The Trinity describes itself as an introduction, readers need to have at least a passing familiarity with the doctrine and its basic terms before they read the book, or they might feel a bit lost in it. My guess is that the Short Studies in Systematic Theology is directed at Bible college students and seminarians, who are the most likely to consume introductory books on systematic theology. I believe pastors and theologically proficient church leaders and members can also benefit from the book. It will enrich their understanding of why sound biblical theology results in Trinitarianism, and it will help them connect what sometimes seems like an abstract doctrine to the Bible’s core concern, namely, God’s salvation of lost humanity.

Book Reviewed
Scott R. Swain, The Trinity: An Introduction (Wheaton, IL: Crossway, 2020).

P.S. If you liked my review, please click “Helpful” on my Amazon review page.
34 reviews1 follower
October 21, 2024
This was a fantastic primer/introduction on the trinity. By no means exhaustive (how could it be), Swain keeps the main thing the main thing, and doesn’t chase any rabbits.

This book is very repetitive, typically a con for most books. However, when studying the One Triune God, it seems good and right to use repetition to the advantage and benefit of the reader. Indeed God is unique, transcendent, and has primacy above and over all creation.

Though repetitive, Swain exercising incredible brevity as he works through both common and proper predications between the Trinity, emphasizing the Oneness of the Three persons, while balancing this with proper distinction between the three persons petting to their mode of origin as being relational.

Solid read for folks of all levels of theological training/understanding.
Profile Image for Zack.
381 reviews67 followers
January 1, 2025
An extremely tight and well-written primer on a perennially difficult (both for its mystery and man’s erroneous opinions) subject. I would have liked to have seen more sustained treatment of the doctrine of divine aseity as it relates to each of the Three Persons of the Trinity, though Swain does make a pass at it on pp. 118f.
Profile Image for Emily.
26 reviews1 follower
September 29, 2023
Lovely introduction to something very complicated, communicated simply in a comprehensive AND comprehendible way for lay people. It will continue to be confusing but that’s the mystery of God’s nature! I appreciated the many scripture references throughout. Do not be fooled, the little green book is DENSE.
Profile Image for Mark Donald.
237 reviews4 followers
December 26, 2021
Great introduction. Helpful in showing how the Bible presents the Trinity. Obviously doctrinal but also devotional. Highly recommend.
Profile Image for Persis.
224 reviews15 followers
January 18, 2021
A concise and helpful intro to the doctrine of the Trinity. It's not a light book because of the topic so it needs to be read slowly and carefully. I appreciate that the book ends with the end of the work of the Trinity, namely the glory of God.
Profile Image for Mr. Perry.
52 reviews6 followers
September 6, 2022
I...like books like this. Short reads about a rather dense subject, packed to the brim with content yet accessible enough for someone to understand what is being discussed (and not get "caught in the woods" in the process). This is what we have here with Scott R. Swain's "The Trinity: An Introduction". It is an intro, and he mentions that a few times. There are other resources that go more in-depth with various Trinitarian concepts/debates, but the book mentions where in history things have been a cause of dissention and gives brief summaries about the debate (and often implications as well - in particular I'm thinking of its' mention of the Filioque). There's also a mention of the three more popular heresies/heterodox views today found in Arianism (Jehovah's Witnesses/Mormonism), modalism (Oneness Pentecostals), and Eternal Subordination of the Son/eternal functional subordination/eternal relations of authority and submission (found from sources such as Wayne Grudem, Owen Strachan, etc) and why they aren't orthodox.

This is a good one if you're interested in a good general overview of the doctrine of the Trinity. Understanding God as expressed in Scripture properly is of utmost importance. This book does well to that end.
Profile Image for Gareth Russell.
84 reviews8 followers
January 20, 2021


I was profoundly disappointed by this book. Scott R. Swain intends to write a book "designed to serve beginning students of theology ... pastors seeking to review the main contours of Trinitarian teaching, and interested laypersons." Such a slim overview would be immensely helpful for the Church. But this is not that book for two reasons:

1. Poorly Written
The book is filled with impenetrable prose, academic speak, and breathless paragraphs that could be a single sentence. So, we read sentences such as: "...we turn from consideration of the one God’s simplicity to consideration of his tripersonal fecundity..." or find incredibly hard to read paragraphs like this:

"Even then, scriptural Trinitarianism retains its status as primary Trinitarian discourse, not just in the sense that the Bible’s Trinitarian discourse is the source and norm of Trinitarian doctrine, but also in the sense that the Bible’s Trinitarian discourse is Trinitarian theology’s normative “pattern” (2 Tim. 1:13) and generative “standard” (Rom. 6:17) for fluent, well-formed Trinitarian praise: its grammar, its lexicon, and its syntax. Everything else is commentary."

The tone of the book is more physics textbook, than a book about the wonder of the triune God.

2. Not Charitable
Swain is dismissive to those who see order in the relationships within the trinity. He equates such views as being a sub-level of heresy and fails to articulate their position clearly or sympathetically. If you already have strong views against Eternal Functional Submission in the Trinity, you'll be nodding along with Swain. Otherwise, you'll be very frustrated.

There's some good nuggets in here. But I wouldn't recommend giving this book to any beginning student of theology, pastor colleagues, or interested laypersons.
Profile Image for Teresa.
185 reviews12 followers
March 5, 2024
I think if I read this again more slowly, while taking notes, and with a dictionary on hand, I might give it 4 or even 5 stars. I’m sure the author probably deserves it. And I’m sure there is a lot of beautiful truth to be gleaned here. But I gave 3 stars mostly because of all the 4 and 5 star reviews here on goodreads that mention how this book is so accessible and easy to understand, even for the lay church member. I am a lay church member with no formal Christian education under my belt, but I’ve studied my Bible for 20 years and enjoy studying theology at various levels of learning. Yet this book was still a pretty difficult read for me, and I felt a little lost in it at times. I thought I’d share this here on goodreads in case there is anyone out there who felt discouraged that this wasn’t as “accessible” to them as many other reviewers have claimed.
Profile Image for curtis .
270 reviews3 followers
October 31, 2020
This short book is a breathtaking introduction to the doctrine of the Trinity, its entailments, and its meaning for the Christian life. Better than any other writer I’ve seen, Swain manages to instruct the reader in all of the most important technical terminology involved in classical Trinitarian theology, yet without sacrificing approachability or accessibility. This was an absolutely enthralling read; it took me only three sittings, and that only because the material was so devotionally provocative that I frequently had to step away to meditate and marvel at the greatness and the goodness and the kindness of the glorious Triune God. This is a book I’ll come back to again and again in the coming years, and one I will recommend without hesitation to every single Christian I know.
Profile Image for Jimmy.
1,184 reviews50 followers
August 21, 2024
Are you looking for a summary book on the Trinity that is under two hundred pages? This is a book I recommend. This is from the Short Studies in Systematic Theology series from Crossway and it’s the second volume I read from this series. Previously I read the book on the Holy Spirit in this series and it impressed me so I was eager to see how the work on the Trinity would turn out. I was also interested to see if it would be as good as the Short Studies in Biblical Theology Series that I have immensely enjoyed reading for years from the publisher.
After the series preface and introduction there is eight chapters. The first two chapters is concerned with the Bible and the Trinity then a chapter on the Simplicity of God. Chapter four through six is the Father, Son and Holy Spirit respectively. This is followed by chapter seven on the shape of God’s Triune Work and the final chapter is on the end of God’s Triune Work (end in terms of goal).
These chapters were immensely helpful to understand the historic and orthodox doctrine of the Trinity as professed by the church for centuries. The chapter on Divine Simplicity was great and the explanation of three types of Trinitarian passages in the Bible in chapter two was also extremely helpful. Don’t take the subtitle that this is “an Introduction” to mean that this is easy. The author Scott Swain does bring it down to make it more understandable for the general reading audience than the typical book on Christian Classical Theism but still it does have a rigor about it. I also appreciated the author’s take on the Eternal Functional Subordination controversy (note: the author is against it) and he addressed the issue without the heat and rhetoric that one sees on social media concerning this topic. I appreciate that. I do recommend this book!
NOTE: This book was provided to me free by Crossway without any obligation for a positive review. All opinions offered above are mine unless otherwise stated or implied.
Profile Image for Hobart.
2,690 reviews84 followers
February 9, 2021
What we find in later Trinitarian creeds, confessions, and doctrinal summaries are not improvements upon a latent or undeveloped biblical Trinitarianism but, rather, the church’s attempt to fathom the depth of the riches of biblical Trinitarianism for the sake of various liturgical, pedagogical, and polemical ends. Some of the church’s creeds, confessions, and doctrinal summaries represent such faithful expressions of scriptural teaching and enjoy such wide-ranging ecclesiastical consensus that we dare not transgress the lines they have drawn. Rather, taking them on our own lips, we gladly join the church’s chorus of Trinitarian praise.


WHAT'S THE TRINITY: AN INTRODUCTION ABOUT?
It's kind of there in the title, right? This is an introduction to the classical Christian doctrine of The Trinity. He's not trying to re-invent the wheel, he's definitely not trying to innovate, but to provide a concise (it's a Short Study, after all) jumping-off point into deeper studies by providing a solid foundation.

He spends two chapters looking at the primary Biblical texts demonstrating the Doctrine. Chapter 3 is about the Simplicity of God—something too many overlook in a discussion of The Trinity. The following three chapters each focus on a Person of the Trinity. The final chapters are about the "external works" of the Trinity, the "appropriation" of specific works to particular persons, the beneficiaries of God's work, and assorted topics.

All of that is a lot to ask of 133 short pages. Swain pulls it off by being concise, but he never seems to be leaving out details or avoiding the complicated ideas (although he obviously has to).

TOUCHING ON CONTROVERSY
This isn't a polemical work—Swain is here to inform and educate, not combat. Still, he does talk about some Christological errors, including the contemporary dust-ups over EFS/ERAS—Eternal Functional Subordination/Eternal Relations of Authority and Submission.

Swain briefly (again, it's a Short Study) addresses this error. He's calm, he's fair, yet he's firm. It's one of the best short treatments of the controversy I've seen, and in the context of the larger discussion of the Person of the Son as well as the larger discussions of each of the Persons, it's incredibly helpful. It also fits where he put it and doesn't seem like Swain used the opportunity as a digression just to beat a pet theological peeve.

HELPFUL SUPPLEMENTAL MATERIAL
Maybe it's just me, but I rarely find the post-text material all that helpful. This book was one of the pleasant exceptions—there's a brief glossary of some of the technical terms. Also, the "Further Reading" suggestions look great and my "To Buy" list grew a bit.

SO, WHAT DID I THINK ABOUT THE TRINITY: AN INTRODUCTION?
Because the persons of the Trinity are internal to God’s life, not external works of God, we can know the persons of the Trinity, as well as their ultimate plan for creation (Eph. 3:9), only if they stoop down and open up the depths of their inner life to us. Only the persons of the Trinity know the persons of the Trinity. Therefore, only the persons of the Trinity can make known the persons of the Trinity. The revelation of the Trinity is a matter of divine self-revelation, divine self-presentation, divine self-naming.

While this is a theological book, drawing on the teaching of the Church, Swain is careful to never lose sight of the source of this Doctrine, the Word of God. We know this, we understand this (as much as we do) because it is revealed to us. That's vital to an understanding of the doctrine, and vital to the teaching of it. Swain doesn't let his readers stray from the text.

This is one of those books where my notes keep saying "Chapter X is likely the highlight of the book," "the section on X is likely the most valuable in the book." It appears 60-70% of the book is a highlight—and I may not have written all of those parts down. Which is to say, there's a lot of gold here, very little (if any) dross.

Helpful, insightful, and useful—it also achieves its end for leading on to further study for me. It's accessible, but not easy, reading. At the same time, it's a challenging, but not difficult, text.

Also, I like the looks of this series as a whole, I'll most likely be grabbing more/all of them if they're all about this quality.
50 reviews10 followers
May 22, 2024
What a great introduction to the Trinity! Swain has done an excellenct job in this short book giving us the broad strokes of the Trinitarian picture revealed to us in scripture. He does a lot in a little amount of space. More accurately, he gives us the proper grammar so that we can speak with clarity about the triune God we worship.

This book, along with Michael Reeve’s Delighting in the Trinity would be a great intro to the doctrine for anyone looking to dive in. Reeve’s is more approachable for most, but Swain’s is precise and worshipful in all the right ways - defining terms well so that we can pray, proclaim and praise our God for who he is: one God in three persons.

Also, he does a great job of dismantling three, all too common, trinitarian errors: moralism and subordinationism, as well as the more recent (but too pervasive) error of eternal functional subordination (EFS) also referred to as eternal relations of authority and submission (ERAS). He, along with scripture and the Nicene Creed, put that one to rest pretty handily considering he does in a few pages what some do in whole books!

Great refresher and read! Highly recommended!
Profile Image for Branden Williams.
2 reviews1 follower
January 21, 2021
This was a great book. It's an "introduction" to one of the most amazing doctrines in the whole Christian faith. Therefore, even an "introduction" requires careful attention and careful reading. Dr. Swain does a wonderful job of explaining the doctrine and all its facets, as well as confronting major heresies such as modalism and eternal subordination. The book is full of scriptural references, showing that the author is not doing systematic theology in thin air, but according to and within the whole counsel of God. As an introduction, I appreciated the dozens of pages of history being left out so that lay persons who read the book don't get too bogged down. It also kept the book to manageable length. The book was well written, complete with glossary, index, and scripture index. If one of my members asks me about the Trinity, I will point them to this book first for further exploration of the doctrine.
Profile Image for Sam Nesbitt.
140 reviews
June 28, 2025
Swain provides a healthy balance of conciseness, clarity, and depth in this introduction to the Trinity that helps beginners learn and refreshes those already familiar with the basics. Swain grounds his explication of the Trinity in the grammar of Scripture, locating the common predicates and the proper predicates for each Person of the Trinity as the One True God. He also helpfully explains the importance of the simplicity of God and its relevance for the Trinity. Juxtaposing biblical and classical theism to heretical teachings and errors, he also helpfully explains the teachings of modalism, subordinationism, and also discusses recent controversies around the supposed eternal subordination of the son. In short, there can be no division of will between the persons of the Trinity, for such a premise would lead to tritheism. Overall, this is a wonderful introduction that is worth returning to for reference on the doctrine of the Trinity.
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