Christians confess that God is one and that the Father, the Son and the Holy Spirit are each God. The way through is a single distinction. God is one in his nature, which is what God is. He is three in his persons, which is who God is. Once that distinction is clear, the doctrine stops reading as bad arithmetic. It starts to explain two things you care about: how God could be love before he made anything, and why the cross was a real act and not a piece of theater.
This guide builds that understanding one step at a time, with Abdu Murray as the main teacher. Murray grew up Muslim, was trained as a lawyer, and became a Christian at 27 after nine years of studying the differences between Islam and Christianity. He once thought the Trinity was absurd. He now calls it his favorite topic. Each step below includes a short task. A group can work through the whole guide in one long session or split it at the heading on love. If you are studying alone, do the tasks on paper and say your answers out loud. Explaining the Trinity to someone else is the real test of understanding it.
For leaders: do not open by asking people to define the Trinity. Most will reach for a picture of water or an egg, and step three takes those pictures apart. Begin with step one and let the definition grow from there.
Step one: two questions you can ask about anything
Every claim about the Trinity depends on a difference between two questions. Murray shows it with an object he had in his hand. Ask what a phone is, and you can answer: a machine, a non-living thing. It has a nature. Then try a second question. “But you can’t say about the phone, who is that?” There is nobody in it to name.
Ask both questions about a person and you get two different answers. What is Abdu Murray? A human being. Who is he? Abdu. A nature is the kind of thing something is. A person is someone who has that nature.
The word “person” is where most confusion starts, so Murray defines it carefully: “What I mean by personhood, and what has classically been meant by this in terms of the Trinity is a center of consciousness.” In everyday speech, “person” means a separate individual, a separate being. In the doctrine, it means a mind that knows and relates to other minds. Hold onto that definition. The rest of the guide depends on it.
Task. Put three things in front of the group: an object, a plant and a photo of someone everyone knows. For each one, answer “What is it?” and then “Who is it?” Notice where the second question has no answer. Then write one sentence, in your own words, that says what the question of nature answers and what the question of person answers.
Now the doctrine can be stated precisely. God has one divine nature. Three persons, Father, Son and Holy Spirit, each fully have that one nature. Murray names the two claims that really would contradict each other: “It’s not one God in three gods or one person in three persons. Those are both contradictory ideas.” The Christian claim is neither. This is essential Christian belief, and Jude 3 teaches it plainly: one God in three persons, co-equal and co-eternal.
Step two: watch the persons in one scene
The doctrine did not begin as a puzzle about definitions. It grew out of how Scripture speaks. Two strands run through the Bible, and both have to be kept.
The first strand is that God is one. Israel’s basic confession is “Hear, O Israel: The LORD our God is one LORD” (Deuteronomy 6:4). Christianity never gave this up. A version of the Trinity that ends in three gods has left the Bible behind.
The second strand is that Scripture speaks of Father, Son and Spirit as distinct from one another and yet all divine. John opens his Gospel this way: “In the beginning was the Word, and the Word was with God, and the Word was God” (John 1:1). Read the verse slowly. The Word is with God, so the Word is distinct. The Word was God, so the Word shares what God is. That is the nature and person distinction appearing in the text before anyone had technical terms for it.
Observation task. Read Mark 1:9-11 aloud. Jesus comes up out of the water. He sees “the Spirit like a dove descending upon him” (Mark 1:10). A voice from heaven says, “Thou art my beloved Son, in whom I am well pleased” (Mark 1:11). Before anyone interprets the passage, list who is present and what each one does. Then ask: does this scene show one person taking turns, or three persons acting at the same moment?
Be careful about how much this scene proves. A narrative describes what happened. It is not a doctrinal definition, and no single scene builds the whole doctrine. The doctrine rests on the pattern across Scripture. That includes the command to baptize “in the name of the Father, and of the Son, and of the Holy Ghost” (Matthew 28:19), where three are named and the word “name” is singular. What Mark 1 does is make one wrong idea very hard to hold, and that wrong idea is the subject of the next step.
Step three: where the familiar pictures fail
Most people first learned the Trinity through a comparison. Murray avoids them for a stated reason: “I don’t like talking about the, the Trinity through analogies because they tend to lead to heresy.” Take the best-known one, water as ice, liquid and steam. He points out that “any one body of water is not simultaneously steam and liquid and solid.” Water takes one form and then another.
Applied to God, that picture teaches modalism, the idea that one person appears first as Father, then as Son, then as Spirit, like an actor changing masks. Murray’s answer is short: “God is always the father. He’s always the son, and he’s always the Holy Spirit.” The baptism in Mark 1 is exactly what modalism cannot explain. The Son is in the water, the Spirit is descending, and the Father is speaking, all at once.
Other pictures fail in the opposite direction. An egg’s shell, white and yolk are three parts, and none of them is a whole egg. That makes each person one-third of God. Three people who share human nature are three separate beings, which makes three gods. Every comparison we have comes from a world where each nature belongs to exactly one person, so every comparison breaks somewhere.
This is not a reason to give up on understanding. Murray borrows a line he once heard on a radio broadcast: “we can apprehend the Trinity, but we can’t comprehend the Trinity.” To apprehend something is to grasp it truly. To comprehend it is to grasp all of it. His summary is worth memorizing: “It may transcend understanding, but it doesn’t defy logic.”
Task. Have the group name every Trinity analogy they have heard. For each one, ask two questions. Does it make the persons appear one at a time? Does it make them separate beings or fractions of God? Then put the analogies away. From here on, use the two questions from step one.
Step four: love before anything else existed
So far the guide has shown that the doctrine is coherent. Murray goes further. He argues that the Trinity explains something any believer in one God already wants to say.
Follow his steps in order. First, if God is the greatest possible being, “he would need nothing to be who he is.” Second, Christians describe God with relational words: loving, kind, compassionate. Third, those words require more than one party. “Compassion requires the compassionate one and the one on whom compassion is given.” Now put the three together. If God were a single person alone before creation, he would need to make someone in order to be loving at all. He would depend on the world to be himself.
A triune God has no such need. Murray describes the Father loving the Son, the Son loving the Spirit, and the Spirit and the Father loving each other, from eternity. Scripture gives a glimpse of this in Jesus’s prayer: “for thou lovedst me before the foundation of the world” (John 17:24). Read that next to “God is love” (1 John 4:8), and love turns out to be older than the universe.
This is where the doctrine changes how a person relates to God. If God needed nothing, then he did not make you to fill an emptiness in himself. Murray puts it this way: “He creates you and me so that we can have relationship with him and be blessed by that communion with the living God.” You were not created to meet God’s need. You were invited into a love that was already full.
A fair test. This argument depends on a premise someone can reject: that love belongs to God’s nature from eternity, rather than being something God expresses only once creation exists. Murray knows the strongest objection from the inside. Muslims, he says, worry that three persons would mean God has helpers: “why does he need the Spirit and the Son to help him?” He insists that objection comes “not based on a desire to misunderstand, but on the desire to actually want to worship God in a valuable way and in a way that doesn’t insult him.” Before anyone answers it, have one person restate the objection in a way a sincere Muslim would accept as fair. Then answer it with step one. A helper is a second being with a separate nature. The Son and the Spirit share the one divine nature, so neither is an addition to God.
Step five: what the cross requires
The same distinction reaches the center of the gospel. Murray holds to penal substitution, the view that Jesus stood in our place and bore the judgment for sin. He states the skeptic’s challenge in sharp terms. If Father and Son are simply the same, the payment on the cross is not a real transaction. “It’s just shifting money from your right pocket to your left pocket.”
The Trinity answers this. The Son shares the Father’s nature, so what he does on the cross is truly God’s own act. The Son is also a distinct person from the Father, so something real passes between them. Murray: “then when the Son on that cross makes that payment, it’s actually real. It’s not an illusion. It’s not a fiction. It’s a real payment.” He adds the third person as well: the Spirit convicts us of sin and brings us to life, so that we trust what the Son has done.
Christians describe the atonement in more than one way, and this guide does not require any group to settle that debate. The point Murray makes holds across those views. A cross where the Son truly gives himself to the Father requires the Son and the Father to be truly distinct. It also changes how a believer lives. In Murray’s words, “we don’t do things in order to get saved. We do things because we are saved.”
Practice: three minutes, no props
Near the end of the conversation, Lisa Fields teases Murray that explaining the Trinity in a three-minute video could go viral. Take the challenge seriously. Pair up. Each person has three minutes to explain the Trinity to their partner using only the what and who distinction, one passage of Scripture, and the reason it matters for love or the cross. No analogies allowed.
The listener keeps score on three common errors. Did the explanation slip into three gods? Did it turn into one person wearing masks? Did it make the Son or the Spirit sound like helpers added to God? Then swap. Leaders, close the practice by asking which error was hardest to avoid and why. The answer usually reveals which step needs another pass.
Questions for discussion
- Before this study, which picture of the Trinity did you carry around? After step three, what did it teach you that turned out to be wrong?
- In your own words, why is saying God is one in nature and three in persons not the same claim as saying there is one God and three Gods?
- Mark 1:9-11 describes a single event. What does it show about the persons, and what would be claiming too much from one narrative?
- Murray’s argument from love depends on love being part of who God is from eternity. Does that premise seem right to you? What would you say to someone who denies it?
- If God did not need to create you, does that make you feel smaller, or more wanted? Talk about why people might answer this differently.
- How would your prayers change if you addressed the Father as someone who has always loved the Son, and the Spirit as the one who leads you to trust that love?
Leaders: questions four and five may divide the group, and that is fine. Let people disagree about how the argument lands while keeping the essential doctrine clear.
Carry this out
Read John 17 once this week, slowly. Each time you notice the Father and the Son speaking to or about each other, ask the two questions from step one. Which words show they share what God is? Which words show they are distinct? By the end of the chapter, you will have watched the doctrine at work in a prayer, which is where it was meant to be lived.