Trinitarian theology is at the heart of Christianity. Though the word “Trinity” never appears in Scripture, the doctrine was so evident to the early church that, despite vigorous debate, the confession that God is Father, Son, and Holy Spirit became enshrined in the earliest creeds of the church.
Many evangelical Protestants, however, give little thought to a robust defense of Trinitarianism. Some might point to a few proof texts like Jesus’s divinity in John 1 or the mention of Father, Son, and Holy Spirit in Matthew 28:19. But is that all there is to say? Has the central dogma of Christianity survived by mere proof texts?
Brandon Smith is on the board of directors at the Center for Baptist Renewal. He is assistant professor of theology and New Testament at Cedarville University and the host of the Church Grammar podcast. In his book The Biblical Trinity: Encountering the Father, Son, and Holy Spirit in Scripture, Smith argues that “seeing the doctrine of the Trinity will require more than mere proof texts or word studies—it will require following the logic and grammar of Scripture” (1).
Even as evangelicals have held strongly to the authority and inerrancy of Scripture, many of us have never been taught how to read it theologically. The goal of this book is not to “prove” the Trinity but to teach basic reading strategies so readers can encounter the triune God in the revelation of his Word.
Necessary Grammar
The Trinitarian grammar consists of four terms: nature, relations, inseparable operations, and the hypostatic union.
Has the central dogma of Christianity survived by mere proof texts?
God’s nature simply means he’s one, so that the Father, Son, and Holy Spirit share the same attributes and will. Eternal relations distinguish the triune persons from one another: the Father is unbegotten, the Son is eternally begotten from the Father, and the Holy Spirit proceeds from the Father and the Son. The concept of inseparable operations maintains God’s unity and distinction by teaching that when one person of the Trinity acts, all three persons are indivisibly working together. The hypostatic union affirms that the eternally divine Son assumed a human nature—truly becoming man—without ever ceasing to be God.
These technical theological terms can turn off the unfamiliar reader. We might wonder how more extrabiblical terms can possibly help us understand the doctrine of the Trinity (itself an extrabiblical term). But that’s like wondering how nouns and verbs help us read sentences.
We teach children parts of speech not to confuse them but because that’s how language already works. Pointing out a noun isn’t imposing something extrinsic onto the sentence—it’s simply categorizing what’s already there.
Theological Assumptions
For Smith, learning to read theologically isn’t about attempting to read Scripture without assumptions but about reading with the correct assumptions. These principles teach us to read in a theological-canonical way, assuming that the Old and New Testaments are a unified story, whose beginning and end is the triune God himself.
Smith makes two fundamental assumptions about the doctrine of the Trinity: (1) it’s rooted in the biblical storyline and (2) it was received by the Christian tradition as a faithful reading of Scripture’s presentation of God.
The reading methods Smith teaches us in this book aren’t new. They’re ancient. But this book does emerge at a crucial time in theological scholarship. Amid theological retrieval efforts in recent years, there have been increasing efforts to retrieve the theological interpretation of Scripture as well.
Applying Biblical Pressure
After setting the groundwork in the initial chapter, Smith walks through 15 passages of Scripture, employing and modeling the reading strategies he’s proposed. As he exegetes selected passages of Scripture, Smith shows that the inherent presuppositions of the biblical text place a certain pressure on the reader to draw theological conclusions.
The reading methods Smith teaches us in this book aren’t new. They’re ancient. But this book does emerge at a crucial time in theological scholarship.
For example, when considering the baptism of Jesus (Matt. 3:16–17) and the Great Commission (28:18–20), Smith notes the inseparability of the Trinity’s act and mission: the Father sends the Son, the Son becomes incarnate, and the Spirit is poured out. Simultaneously, we see that the Father isn’t down in the water, the Son doesn’t descend from heaven like a dove, and the Spirit doesn’t speak from heaven.
At the Great Commission, Jesus called his disciples to baptize in the one name of the three persons. Smith summarizes: “This is not a contradiction, but rather the way the text pressures us to make sense of God’s unity and distinction” (25). This notion of internal pressure helps us understand the biblical basis for the doctrine of the Trinity.
Retrieving Ancient Resources
The approach of this volume requires the appropriate use of ancient resources. Good theological reading relies on the consensus of the early church and dialogues with the saints who’ve gone before. For example, while exegeting John 1:1–18, Smith employs the Nicene Creed, calling it a “theological summary of John 1” (39). When assessing Jesus’s divine claims in John 5:17–20, he draws upon Chalcedonian language: “Two natures, without confusion, without change, without division, without separation” (45).
Smith cites a host of ancient voices like Irenaeus, Origen, Athanasius, Hilary, Augustine, the Cappadocian Fathers, and Chrysostom. Yet his reliance on the church fathers never feels forced. Consistently, Smith’s reliance on ancient writings helps to clarify points of modern confusion.
Doxological Doctrine
The most helpful aspect of this volume is its constant posture of worship. Rather than engaging in theological abstraction, Smith exegetes with a refreshing awareness that he’s talking about the true and living God. Each chapter ends with a short, theologically rich prayer.
Smith consistently reminds us that the purpose of this book isn’t simply to show that the Trinity is biblical or demonstrate that the Bible is Trinitarian. The primary goal is to unveil the deepest purpose of the Bible—which is to reveal the Holy Trinity—so we might commune with the Father, Son, and Holy Spirit, today and forevermore. The Biblical Trinity achieves its primary goal, equipping readers for a life of deeper worship and devotion to the triune God.
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