from 40 Questions About the Trinity by
Matthew Y. Emerson and R. Lucas Stamps
The doctrine of the Trinity is central to the Christian faith because the triune God is the central object of our faith. In other words, we study this doctrine because we are trying to understand the God in whom we have faith, for whom we were made, and by whom we are saved. If you want to grow as a Christian, you need to understand the God who has made himself known to you in Jesus Christ. However, as important as this doctrine is, Christians often treat it as a theological hoop to jump through or a strange alleyway in an otherwise interesting and enlightening walk through the other major Christian doctrines. Let’s begin by looking at a few reasons why Christians don’t often believe this central doctrine is important to their life of faith.
While the historical development of the doctrine is fascinating in its own right, we should be ever mindful that divine election is first and foremost a biblical doctrine rooted deeply within the Old and New Testaments. Though various theological traditions hold to specific beliefs about this doctrine, election itself does not belong to them but to God. It is Scripture that teaches us that God elects and how he goes about it. As such, we will begin our study by exploring the Scriptures in an attempt to develop a biblical definition of election, then we will explore how this definition unifies Christians while leaving room for differences of opinion.
Why Some Christians Think the Doctrine Isn’t Important
Unfortunately, many Christians have mistaken notions about the doctrine of the Trinity that prevent or deter them from studying it. Sometimes Christians mistake this doctrine for another theological box they have to check in order to be considered “orthodox.” In this scenario, the doctrine isn’t something that makes a difference in their real life or ministry, but just something we must affirm to be called a Christian. So, often we’ll say “yes” if someone asks if we believe the doctrine of the Trinity but only because we were taught it in a new members or confirmation class, not because it really makes a difference to us or to our faith.
A related mistaken notion is that the doctrine is unimportant specifically with respect to evangelism. Some of our popular gospel presentations include little, if any, reference to the doctrine of the Trinity or even to the fact that God is triune. The emphasis is squarely on our sin and need for a savior, a savior who has restored us to God through the crucifixion of Jesus. Of course, we are sinners in need of a savior, and God did provide salvation for us in the death of Jesus on the cross. But these elements of the gospel presentation are so emphasized that they often lead to the exclusion of any explanation of who Jesus is as the Second Person of the Trinity in the flesh (or of the resurrection, Jesus’s life, or the Holy Spirit, for that matter). Because many people come to saving faith in Jesus without understanding, much less hearing about, the doctrine of the Trinity, they think it is unimportant in comparison to other doctrines, in comparison to the kind of gospel presentation that led to their own conversion, and especially in comparison to “real life.”
Finally, some Christians believe that the doctrine of the Trinity is only for academics. This notion comes in various forms, including those mentioned above, but here we want to focus on one particular version of this mistaken notion: that its academic focus is a result of it not being taught clearly in the Bible. If it were taught clearly in Scripture, more Christians would care about it. But since it isn’t (so this objection goes), only those in ivory towers care deeply about something so esoteric and intellectual.
We will deal with each of these mistaken ideas in one way or another throughout the book. In this chapter we want to focus on four reasons that we should find the doctrine of the Trinity important and, in fact, central to our Christian faith and practice.
Why the Doctrine of the Trinity Is Important
The doctrine of the Trinity is important. In fact, it is absolutely crucial to Christian theology, to the church’s worship, to evangelism, to the Christian life—to everything. This is because the doctrine of the Trinity is the doctrine of who God is—the God who made everything, the God who saved us by becoming one of us and dying for us in the person of his Son, the God who will make all things new when Jesus returns. Every single thing in existence—including other Christian doctrines, daily devotionals, corporate worship, and gospel presentations—owes itself to this one God, the triune God, Father, Son, and Holy Spirit, the God who has revealed himself to us in his incarnate Son, Jesus Christ, by his Holy Spirit.
So, other than this totalizing claim about all of reality, why is this doctrine so important? First, the doctrine of the Trinity is important because Scripture teaches it. Christian faith and practice must be derived from God’s revealed, inspired, and inerrant word, the Bible. Anything that isn’t taught in the Bible should not be taken as necessary for Christian belief and discipleship. But anything that is clearly taught in Scripture is required for the Christian life, and this includes the doctrine of the Trinity. We’ll dive deep into how the Bible teaches the doctrine of the Trinity in part 2, but we want to say up front that this doctrine is thoroughly and explicitly biblical.
A second reason why this doctrine is important for Christians is because our study of it helps us obey the first commandment as well as the Greatest Commandment. In order to “have no other gods,” we have to understand exactly who the One God is. And in order to love God with our whole mind, we have to grow in our knowledge of the triune God, Yahweh. The life of discipleship is not limited to gaining information, but it also cannot proceed without careful study of Scripture and its teachings about God, humans, creation, and salvation. In other words, we are not brains on a stick, but we should also not leave growth in our knowledge of God and his Word to the “professionals,” whether they be pastors, professors, or Bible nerds.
Of course, our knowledge of God isn’t intended to remain purely information; it is for transformation. Studying who God is leads us to worshiping him and submitting our lives to him. In this respect, a third reason that this doctrine is important is because studying it prompts us to pray and impacts our life of prayer. [1] Study of the Trinity leads to prayer because we cannot have any other proper response to contemplating who God is than to bow down before him. But it also should impact our prayer life, or the way that we pray. Understanding this doctrine helps us to understand that when we pray, we do not only pray to one of the divine persons but to the triune God.
Obviously Jesus commands to pray to “Our Father” (Matt. 6:9) and to ask “in my [Jesus’s] name” (John 14:13), and there are numerous instances throughout Scripture where someone’s prayer is described as “in the Spirit” (Eph. 6:18; Jude 20). So it is not as though we cannot or should not pray to the Father, in the name of the Son, and by the power of the Holy Spirit. But, as we will see later, while this formula is indicative of what is called Trinitarian taxis, or order, it does not mean that we only pray to one person at a time. Instead, we are always praying to the triune God, even if we direct some of our requests to one of the three divine persons.
More generally, the ultimate aim of our worship of the triune God— including prayer to him—is fellowship with the triune God. We think about and sing about and pray to God in order to dwell with God. We human beings, image bearers of the triune God, are made for this worshipful communion. This leads to a fourth reason that theology broadly, and study of the doctrine of the Trinity in particular, is important: because it is ultimately in service of this doxological purpose, this end goal for every human life.
Finally, the doctrine of the Trinity is important because without it we can’t get the gospel right. You need to understand who God is as triune in order to understand his Trinitarian work of salvation. It is the one God who saves us, who redeems us to himself. He does so in accordance with who he is: namely, the Father, Son, and Holy Spirit. The work of salvation, just like God’s other external work—creation—is necessarily Trinitarian because God himself is triune. The Father sends the Son, the Son is sent by the Father, and the Holy Spirit is the agent of the Father’s sending and the Son’s sent-ness. The Father authorizes the incarnate Son’s mission at his baptism, the incarnate Son pursues and fulfills his mission throughout his life and in his atoning death, and the Spirit anoints and empowers the incarnate Son for his mission. The Father hands the incarnate Son over to the Roman and Jewish authorities to be crucified, the incarnate Son lays down his life on the cross, and the Spirit sustains the incarnate Son in his crucifixion. And so on.
We will discuss this later in the book, but we need to be clear here that each person of the Trinity is not acting separately in these events. Instead, the one God is accomplishing the one act of salvation in Trinitarian fashion. This Trinitarian grammar for the doctrine of salvation is required if we are to understand the gospel rightly: It is the triune God who saves us, not only one of the divine persons.
But there is another reason why the doctrine of the Trinity is important for understanding the gospel rightly, a reason that was particularly emphasized in the early church. If each of the three divine persons are not fully God and one God, then the gospel isn’t true. In fact, it can’t be true. If the Holy Spirit or the Son isn’t fully God, then it is impossible for either or both of them to ever bridge the gap between us and God that is caused by our sin. They must both be on the “God” side of the equation, so to speak (a concept to which we’ll return later), in order to bring us away from our creaturely and sinful side of that same equation and back to God.
Summary
Understanding the Trinity rightly matters because it’s taught in Scripture. If God has given us “all things that pertain to life and godliness” (2 Peter 1:3), if his words are eternal life (John 6:68), if in preaching the word of God we save both ourselves and our hearers (1 Tim. 4:16), if the word of God is living and active, and if the doctrine of the Trinity is taught in that same word, then it is something we should, we must, take seriously.
The reason why the Bible teaches this doctrine is because it concerns our ultimate purpose as human beings—to know and love the one true God. If we don’t study the doctrine of the Trinity, our worship will suffer as we become unsure or even wrong about who the God we are trying to pray to and worship actually is. It will suffer as we become unsure or even wrong about the good news of the gospel. If each of the three persons isn’t fully God, how could they ever bring us into right relationship with the one true God? For these reasons, we should take this doctrine seriously and doxologically.
[1] See Medi Ann Volpe, “Living the Mystery: Doctrine, Intellectual Disability, and Christian Imagination,” Journal of Moral Theology 6 (2017): 87–102. I owe this reference to Nate Martin.
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This post is adapted from 40 Questions About the Trinity by Matthew Y. Emerson & R. Lucas Stamps. This title is set to be released on September 30, 2025. If you are interested in adopting this book for a college or seminary course, please request a faculty examination copy. We will also consider requests for your blog or media outlets.
Trinitarian theology sits at the heart of Christian doctrine, yet how many believers understand this foundational truth of the faith? Perhaps more importantly, how many believers understand what is at stake in holding to a biblical understanding of this core tenet of the faith? In this primer on Trinitarian theology, readers are invited to ask forty pertinent questions about Trinitarian theology, including:
- What Is the Trinity?
- Why Is It Important for Christians to Know the Doctrine of the Trinity?
- What does the Bible Teach Us About the Trinity?
- What Happened to the Trinity at the Cross?
- How Do We Apply the Doctrine of the Trinity to the Christian Life?
Ultimately, questions about the Trinity are questions about God. Taking the time to prayerfully explore and answer such questions will lead one to a deeper knowledge of him. 40 Questions About the Trinity provides helpful and encouraging guidance for this endeavor.
