What is a Good Illustration for the Trinity?

By James M. Rochford

Does the Trinity confuse you? It might seem counterintuitive, but this might actually serve as evidence that we are encountering the true God. Without a doubt, the Trinity is difficult to grasp. Yet, why should we expect anything else from the infinite and transcendent God? When we study God’s nature, we are exploring the core mysteries at the foundation of reality itself. What could be more profound than the study of God’s essential being? Surely, we should expect a sense of vertigo as we study the infinite-personal God.

When a professor tells us that light is both a wave and a particle, we marvel at such an enigma. But we don’t call her a liar for asserting such a statement. We simply realize that the foundation of reality is far deeper and more profound than we ever expected.

Yet, what happens when we drill all the way down to the foundation of reality itself—to the very nature of God. Why would we expect the foundation of all of reality to be easy to comprehend? God himself said, “To whom would you liken Me and make Me equal and compare Me, that we would be alike?” (Isa. 46:5). Good question! Nothing in creation is comparable to the transcendent God. In Job, we read, “Can you discover the depths of God? Can you discover the limits of the Almighty?” (Job 11:7) The obvious answer? No way! If such an infinite being exists, what makes us think that we could easily grasp what he is like?

Consequently, the complexity of the Trinity points toward its authenticity. After all, if humans were inventing a deity to worship, can we really believe that they would’ve invented a theological idea like the Trinity? This concept is so confusing and mind-bending that “no one would have invented it.”[1]

C.S. Lewis challenges us to think of three-dimensional space from the perspective of someone living in a two-dimensional world. A two-dimensional world would only contain shapes such as squares. But in a three-dimensional world, we would have a cube. Lewis writes,

As you advance to more real and more complicated levels, you do not leave behind you the things you found on the simpler levels: you still have them, but combined in new ways—in ways you could not imagine if you knew only the simpler levels… On the Divine level you still find personalities; but up there you find them combined in new ways which we, who do not live on that level, cannot imagine. In God’s dimension, so to speak, you find a being who is three Persons while remaining one Being, just as a cube is six squares while remaining one cube. Of course we cannot fully conceive a Being like that: just as, if we were so made that we perceived only two dimensions in space we could never properly imagine a cube. But we can get a sort of faint notion of it. And when we do, we are then, for the first time in our lives, getting some positive idea, however faint, of something super-personal.”[2]

Building upon Lewis’ illustration, Michael Jones[3] compares our knowledge of a cube to a tesseract—a four-dimensional cube. Put simply, a tesseract is to a cube, what a cube is to a square. Such a concept is truly mind-bending to people living in a three-dimensional world. Jones argues that this concept is unfathomable, but it is far from illogical. Indeed, if we cannot comprehend it, how could we begin to claim that it is illogical?

Before moving forward, we should address the oft-repeated claim that the doctrine of the Trinity is a “mystery.” Truly, it is a mystery. However, this shouldn’t be an excuse for intellectual laziness. When a detective surveys a crime scene, the perplexing and puzzling evidence causes him to investigate more—not less. Similarly, when Christians use the term “mystery” to describe the Trinity, they shouldn’t use this as a disguise for intellectual apathy. God wants us to love him with our minds. So, let’s get to it.

Assessing Illustrations

No perfect illustration exists for the doctrine of the Trinity. However, many useful illustrations exist. We disagree with theologians who are so focused on precision that they are hypercritical of any and all illustrations. Indeed, what’s the alternative? Will we simply have nothing to say if someone is struggling to grasp this complex concept? We agree with Geisler when he writes, “No illustration of the Trinity is perfect, but some are more helpful than others.”[4]

It is simply impossible to explain such an abstract concept without appealing to an analogy. Practically speaking, we owe it to both young and old Christians to develop good illustrations to help them grasp this deep theological concept. Indeed, by discussing and evaluating various illustrations, we can often gain more precision of the doctrine of the Trinity.

What are we looking for in a useful illustration for the Trinity? We’ve already established that perfection is not the goal. But then, what is? We think four criteria need to be considered when forming a useful illustration for the Trinity:

Criterion #1. Distinction. The illustration needs to show a distinction of three discrete parts. Each part needs to be truly distinct from the other parts, and it also needs to be distinct from the unified essence of the object. Denying this leads to Modalism, collapsing God’s nature into one person—not three.

Criterion #2. Common essence. The illustration needs to show a common essence that is fully invested in each part—not split into thirds. Denying this leads to Tritheism, claiming that there are three gods.

Criterion #3. Simultaneity. The three parts need to possess the same essence at the same time. The parts cannot gain and lose this essence. Denying this leads to Modalism.

Criterion #4. Appealing. Ideally, any illustration should be winsome and attractive to the listener. Otherwise, the doctrine can be associated with a monstrous or bizarre image of God. This could do more harm than good.

The goal in identifying a good illustration is to look for something that has “three different elements [existing] in an undivided oneness at the same time.”[5] We will evaluate common illustrations below.

Heretical Illustrations

“The Trinity is like three men who share a common human nature.” This illustration passes the first criterion, because the men are distinct from one another. However, it fails to pass the second criterion, because they don’t share from the same human substance. All three men share an identical human nature, but they don’t all share the same human nature. Thus, this analogy “leads to tritheism or a pantheon, not the Trinity.”[6]

“The Trinity is like water. The one substance of water can exist in three different forms: liquid, ice, or vapor.” This illustration regularly circulates throughout Christian circles, but there’s just one problem with it: It’s heretical! It doesn’t pass criterion number three, because the different forms of water are not simultaneously water. In the illustration, the water transitions from liquid to solid to gas. But it doesn’t exist in these separate states at the same time. In order for this illustration to work, the same drop of water would need to be “in all three states at the same time.”[7] Thus, this illustration depicts a form of Modalism: God merely appears as three persons, but doesn’t subsist in three persons.

“The Trinity is like an egg. It is composed of an eggshell, an egg yolk, and an egg white.” This illustration shows that each part of the egg is distinct. However, it fails the second criterion: Each of these parts of the egg do not possess the same essence. In order to make this illustration work, the eggshell (or egg yolk or egg white) would need to be considered an egg, rather than part of an egg. By contrast, we wouldn’t say that Jesus is part of God, but that he is God.

“The Trinity is like a three-leaf clover.” This illustration passes the second criterion, because the plant has one essence. However, it fails to pass the first criterion, because each leaf is not truly distinct from the plant itself. Consequently, “each leaf is only one-third of the whole, while the three persons of the Trinity are both together and severally the whole God. This analogy destroys the deity of the three and reduces once again to modalism.”[8]

“The Trinity is like an actor who plays three different roles in a play. In the same way, God manifests himself as the Father, the Son, and the Holy Spirit, but these are all the same God.” This fails the first criterion horribly, and it is a heretical illustration. God is simultaneously three persons—not one person playing three roles sequentially. This analogy illustrates Modalism. The Trinity teaches that God is not merely appearing as the role of the Father or Son or Holy Spirit. Rather, the Son actually is distinct from the Father and the Holy Spirit.

Mediocre Illustrations

“The doctrine of the Trinity is like three links in a chain.” This illustration fails the second criterion: Each link in the chain is not itself a chain. It might have the essence of being metal, but not the essence of being a chain—only one-third of a chain. Geisler writes, “God is only one thing (substance), not three different ones joined together in some way.”[9] Thus, this illustration leads to Tritheism—not the Trinity.

“One to the Third Power.” One to the third power can be depicted as 13 or 1 x 1 x 1 = 1. In this illustration, the “three ones” are distinct, but they equal only “One.”[10] This is different from Tritheism that states that 1 + 1 + 1 =3.

The difficulty with this illustration is simply that it blurs the distinctions of persons and essence. The number one describes both the persons and the essence. Each number (“1”) is identical to each other number. This would make the persons identical—not distinct. Arguably, this doesn’t pass the first criterion of having distinct parts, and possibly, it makes each part identical because each is identified by the same signifier (“1”).

“The nature of love is trifold.” Augustine[11] originated this illustration to describe the Trinity. He argued that it is impossible to express love without a subject who expresses love, an object who receives love, and the spirit of love between the two. Thus, love requires three elements: The lover, the beloved, and the love itself. Though love is one in essence, it necessarily requires all three elements for it to exist.

This illustration doesn’t pass the first criterion: While the component parts are distinct, they are not all the same. Two are persons, and one is an abstract “spirit of love.” This seems to equate the Holy Spirit with an abstract quality—not a personal being.[12] At most, this shows two persons—not tri-personality. Moreover, it fails the second criterion because “it only refers to a quality and not at all to a substance possessed in common by the subject and the object.”[13]

The benefit of this illustration is that it passes the fourth criterion beautifully. It contains a “a personal dimension, in that love is something only a person does.”[14]

Useful Illustrations

A music chord contains three notes.” The notes are distinct from one another, but they all constitute the full chord. They each have the essence of music, but they have distinction from one another as different notes.

This illustration is quite good. It passes the first criterion, because each note is distinct from every other note. The C-note is not the E-note, and the E-note is not the G-note. It also passes the second criterion: Even without the other two notes, each individual note possesses the essence of music. Furthermore, this illustration passes the third criterion, because each musical note possesses the essence of music simultaneously—not sequentially. Finally, this illustration passes the fourth criterion, because it shows the resonance, harmony, and beauty of the Trinity.

If we want to get picky, however, we could say that the musical chord is the essence—not the musical sound. However, a musical chord cannot be reduced to only one note. This would fail the second criterion—namely, the essence cannot be split into thirds.

“The Trinity is like Neapolitan ice cream. There is one ice cream, but three distinct flavors: vanilla, chocolate, and strawberry.” This passes the first criterion, because the three flavors of ice cream are distinct from one another. It passes the second criterion, because each flavor of ice cream is fully ice cream in its being. It would be fair to look at the vanilla ice cream and call it fully ice cream. It passes the third criterion because each flavor is simultaneously ice cream. Finally, it arguably passes the fourth criterion of being appealing. (After all, who doesn’t like ice cream?)

This is a useful illustration. To be honest, it took a while to understand what was wrong with it. However, upon reflection, the problem is that we are confusing the persons with the essence in the analogy. If you noticed, we made a subtle shift when discussing the second criterion. We substituted “ice cream” in general for “Neapolitan ice cream” in particular. If we do this, the analogy breaks apart. If the individual flavors represent the persons of God, then the flavor of Neapolitan cannot also represent the essence of God. Otherwise, this is confusing categories.

Think about it like this: What is essential to the flavor of Neapolitan ice cream? In order for it to be considered Neapolitan, it requires all three flavors. If we only had vanilla, we could still call it ice cream, but we couldn’t call it Neapolitan ice cream.

For the illustration to work, each individual flavor (chocolate or vanilla or strawberry) would need to be Neapolitan (all three flavors at once). But this is contradictory. It would be similar to saying, “The persons of the Trinity are all three persons at once.” Thus, each individual flavor of ice cream does not truly possess the essence of Neapolitan. Unfortunately, therefore, this illustration doesn’t pass the second criterion, because each flavor is only one third of the whole. This leads to Tritheism. However, while it isn’t a perfect illustration, it is certainly a useful one.

“The Trinity is like a triangle. It is one triangle, but it has three separate angles.” This illustration passes the first criterion because each angle is distinct from every other angle. It faces problems with the second criterion, however, because each angle of the triangle doesn’t fully possess the essence of being a triangle. We would never call one of the angles a “triangle.” That being said, we find this illustration useful if we make this clarification.

“The Trinity is similar to the mythical dog “Cerberus” from Greek mythology. In this ancient Greek legend, Hercules had to capture this three-headed dog, who guarded the gates of Hades. Cerberus was one dog in essence, but he had three distinct centers of consciousness.” Craig and Moreland[15] offer this illustration for the Trinity. In this Greek myth, Cerberus had three brains and three distinct centers of consciousnesses. Yet, Cerberus was still only one dog. Imagine if we named the three heads Rover, Bowser, and Spike. If Spike bit Hercules on the leg, Hercules could say, “Cerberus bit me on the leg,” or he could also say, “Spike bit me on the leg.” In this way, this illustration describes a being that is three-in-one.

This illustration passes the first criterion, because each head of Cerberus is distinct from the others. Moreover, it passes the second criterion of having a unified canine essence that exists in each head of the dogs. Each head is fully canine—not one-third canine. Furthermore, this illustration passes the third criterion: The three heads each possess a canine essence simultaneously—not sequentially.

The obvious problem with this illustration (or that of “conjoined twins”[16]) is that it fails criterion number four miserably: It gives a monstrous and bizarre image to associate with God! This illustration compares the infinite-personal God to a snarling three-headed monster invented in Greek mythology! What could be more offensive to Unitarians?

“Allah and the Qur’an.” In Islamic theology, the word of Allah is co-eternal with Allah, and yet it is distinct from Allah: “The Qur’an is not identical to Allah, and yet it is one with God, who supposedly expressed Himself in the words of the Qur’an.”[17] This illustration could be helpful as a starting place for speaking to Muslims about the Trinity. We consider this illustration useful for engaging with Muslims—obviously not secular people.

[1] Millard Erickson, Christian Theology (Second Edition. Grand Rapids, MI: Baker Book House. 1998), 367.

[2] C.S. Lewis, Mere Christianity (HarperCollins, 1996),

[3] Michael Jones, “The Trinity Explained.” InspiringPhilosophy. Published November 4, 2016.

[4] Norman L. Geisler, Systematic Theology (Arlington, TX: Bastion Books, 2021), 551.

[5] Norman L. Geisler, Systematic Theology (Arlington, TX: Bastion Books, 2021), 551.

[6] Robert Letham, The Holy Trinity (Phillipsburg, NJ: P&R Publishing, 2004), 24.

[7] Norman L. Geisler, Systematic Theology (Arlington, TX: Bastion Books, 2021), 551.

[8] Robert Letham, The Holy Trinity (Phillipsburg, NJ: P&R Publishing, 2004), 24.

[9] Norman L. Geisler, Systematic Theology (Arlington, TX: Bastion Books, 2021), 551.

[10] Norman L. Geisler, Systematic Theology (Arlington, TX: Bastion Books, 2021), 551.

[11] Augustine, On the Trinity 8.10.14; 9.2.2. Augustine states that this is “an image of the Trinity in man” (14.8.11; 15.8.14).

[12] Robert Letham, The Holy Trinity (Phillipsburg, NJ: P&R Publishing, 2004), 22.

[13] L. Berkhof, Systematic Theology (Grand Rapids, MI: Wm. B. Eerdmans publishing co., 1938), 90.

[14] Norman L. Geisler, Systematic Theology (Arlington, TX: Bastion Books, 2021), 551.

[15] J.P. Moreland and William Lane Craig, Philosophical Foundations for a Christian Worldview (2nd ed., Downers Grove, IL: IVP Academic, 2017), 1209-1210.

[16] Millard J. Erickson, Making Sense of the Trinity, 3 Crucial Questions (Grand Rapids, MI: Baker Academic, 2000), 63-64.

[17] Norman L. Geisler, Systematic Theology (Arlington, TX: Bastion Books, 2021), 552. For further study, see Geisler and Saleeb, Answering Islam (2012), chapter 12.