Abstract: Ryan Robertson and Matt Bennett explain why missionaries need to understand the Trinity in order to proclaim the gospel accurately. Since the God revealed in Scripture and in the person of Christ is Triune, missionaries should be able to explain and answer objections concerning alleged contradictions between Christ’s divine and human natures. While the doctrine of the Trinity will always contain mystery, we need to make sure that we’re not pointing people to a false view of God.
Editor’s Note: This article is an excerpt from The Path to Being a Missionary by Ryan Robertson and Matt Bennett, ©2026. Used by permission of Crossway, a publishing ministry of Good News Publishers.
For many Christians, talking about the Trinity causes trepidation. After all, church history has shown us that a single letter can mean the difference between heresy and orthodoxy. At the Council of Nicaea, Arius espoused a Christ who, in relation to God the Father, was homoiousios—of like nature—in opposition to Athanasius’s contention that Jesus must be homoousios—of the same nature. That extra letter distinguishes Jesus the Son of God who secures salvation for all who trust in him from a creature who cannot save anyone.
An aspiring missionary might be tempted to think that discussions about homoousios, eternal generation, inseparable operations, and the hypostatic union are interesting for the classroom but irrelevant to the mission field. I could not disagree more. The first job of a missionary is to speak about God, and God has spoken first about himself. If we are to declare this God, then we must be equipped to do so with biblical and theological precision. Without such clarity, we may inadvertently invite our hearers to place their faith in a different god.
For the rest of this article, I’ll alert you to a few Trinitarian discussions you need to have as your neighbors ask questions about God and the Bible. We’ll consider three passages of Scripture that demand a Trinitarian answer.
The Shema and the Trinity
The Bible opens with the bold statement: “In the beginning, God created the heavens and the earth” (Gen. 1:1). The rest of the Bible tells us more about this Creator God. In Deuteronomy 6:4, often called “the Shema” (named after the Hebrew word for “hear” with which the verse begins), we learn that this God is one: “Hear, O Israel: The Lord our God, the Lord is one.” This brief confession plays a key role in ancient Israel’s understanding of the God who has covenanted with them for their salvation. It must be passed down to future generations and put on display in their houses (Deut. 6:4–9). What does it mean that the Lord is one? It means that God exists as a singular essence or nature; he isn’t comprised of various parts.11 . Scott Swain, The Trinity: An Introduction (Crossway, 2020), 53–54.
At the same time, Paul—a Hebrew of Hebrews, well-trained in Scripture and theology—is not embarrassed to teach the Shema in such a way that includes both the Father and the Son. Consider 1 Corinthians 8:6: “Yet for us there is one God, the Father, from whom are all things and for whom we exist, and one Lord, Jesus Christ, through whom are all things and through whom we exist.” Here Paul uses the Shema to frame his statement, yet he recognizes both the Father and the Christ as God. This corresponds to what John affirms in his Gospel as he testifies to the incarnation and speaks of one who both is with God and is God (John 1:1–18). Furthermore, the Scriptures tell us that the Father and the Son have sent the Holy Spirit (John 14:26; 15:26). Peter tells Ananias that to lie to the Holy Spirit is to lie to God (Acts 5:3–4).
The Trinity, of course, is in one sense mysterious. We could not discern it on our own, without the help of God’s revelation. At the same time, it is a mystery that has been revealed and, therefore, a mystery for which we are responsible (Eph. 3:1–7). It’s perfectly appropriate, then, for a missionary to teach a new believer the answer to the question, “How can God be both one (Deut. 6:4) and three (Father, Son, and Holy Spirit)?”
The Trinity and Christology
Christians will encounter questions about the Trinity as they read the Gospels and observe Jesus doing some things that are clearly divine and other things that are palpably human. A new believer from an Islamic environment will ask questions like this: If Jesus is God, then how can he say that the Father is greater than he is? How can he pray to his Father, “Not my will, but yours be done”? How can he cry out from the cross, “My God, why have you abandoned me?” Their Muslim family members taught them these verses to dispute the Trinity. Now they’re reading them in the Bible, wondering how to make sense of them.
These questions demand answers, and missionaries need to be equipped to offer them. To answer the first question, we must be clear regarding the difference between God as he is in himself and God as he acts in redemption. From eternity past, the Father, the Son, and the Holy Spirit have always been equal; none of the persons is ontologically subservient to the others. However, to accomplish salvation, the Father sent the Son into the world. In doing so, the Son became a servant, which allows Jesus to speak of the Father as one superior to himself without diminishing his equality of being, nature, and essence.
To answer the second question, the missionary needs to understand how Christ’s two natures relate to his life and teaching in the Gospels. Jesus’s prayer does not indicate that there are opposing wills within the Trinity. There is one will because there is one nature. However, once the Son assumed a human nature in the incarnation, he also assumed a human will. This human will can—and should—be submitted to the divine will. Adam failed to submit his will to God’s. As the second Adam, Jesus demonstrated the created intention for humans in relation to God and submitted his human will to the divine will—even to the point of death.
Finally, missionaries need to be trained in hermeneutics. When we encounter Jesus’s so-called cry of dereliction from the cross (Matt. 27:46), we need to remember that he’s citing Psalm 22. Once we identify such citations and explore their context, we see that this reference to Psalm 22 is actually a statement of trust. Despite the apparent evidence of God’s abandonment of his Son on the cross (Ps. 22:1), in reality, he is near and has not turned his face away (Ps. 22:24).
The Trinity and Salvation
We must recognize that it’s not just our doctrine of God that hangs in the balance of our Trinitarian awareness. Our ability to make sense of our salvation requires the Trinity. If sin is a transgression against an eternal God, then only an eternal God can remit it. Indeed, the Pharisees identified this reality in their critique of Jesus just before he healed the lame man in Mark 2:7: “Why does this man speak like that? He is blaspheming! Who can forgive sins but God alone?”
To accomplish our salvation, Jesus cannot merely be sent from God; he must be God himself. Likewise, if the incarnate Jesus ascends to his Father while promising to remain with his disciples to the end of the age, then the Spirit he sends must be God. And if the Spirit who dwells among us is God, then Jesus’s salvation must be effective. Otherwise, we would be destroyed for trying to approach the holy and righteous God while we remain in our sin (see Lev. 10:1–3).
The Trinity is not a fusty, old doctrine that has no relevance to missionaries on the front lines. It is the fountainhead of our theology and the basis for the salvation God has accomplished. As Michael Reeves argues, “Because the Christian God is triune, the Trinity is the governing center of all Christian belief, the truth that shapes and beautifies all others.”22 . Michael Reeves, Delighting in the Trinity: An Introduction to the Christian Faith (IVP Academic, 2012), 16.
As missionaries disciple and evangelize, they must ensure that the God they are declaring is in fact the one true God. Temptations will abound to compromise for the sake of apparent communication or maintaining relationships. We must both avoid those temptations and pursue clarity for ourselves in understanding who God has revealed himself to be.
