What Is a Theological “Mystery”?

Human head silhouette with question mark concept

Most people appeal to mystery at some point in their theology. And that’s what we would expect given that we’re trying to understand the infinite, transcendent, and ultimately incomprehensible God of the universe. So we end up talking about things like the Trinity (three persons in one being) and the incarnation (divine and human in one person), fully aware that we are affirming truths that transcend our understanding, but unwilling to say that they are mere contradictions. So we call them mysteries.

But what exactly does it mean to say that something is a “mystery” in theology?

In their book, The Mystery of God: Theology for Knowing the Unknowable (Baker, 2012), Steven Boyer and Christopher Hall explain that “mystery” is actually a rather slippery term in theology. So they offer a helpful taxonomy of different kinds of mystery, arguing that only the last is really adequate to a God who both transcends knowledge and makes himself truly known.

1. An Investigative Mystery

This kind of mystery is the one we see in movies all the time. The mystery presents an intriguing puzzle, a problem that seems impossible to resolve at first. But once some really attractive detective and his/her quirky partner has assembled all the information in the right way, you see how the puzzle can be resolved, the mystery solved.

In other words, this is the mystery of insufficient information. Once we have all the pieces of the puzzle, it’s at least possible that we’ll put them together in the right way and see the whole picture.

Interesting as this might be, Boyer and Hall point out that this is the least helpful definitions for theology. The theological mysteries involved in understanding an infinite God are not just about insufficient information, as though we could assemble all the relevant bits of data about God’s nature and eventually know him perfectly.

2. The Mystery of God’s Plan

The most common biblical use of the word mystery refers to some aspect of God’s plans for creation that had not yet been revealed but have now been made known (e.g. Mk. 4:11; Eph. 3:3). At first this doesn’t sound any different from the first kind of mystery. After all, here as well the problem seems to be a lack of information. Once God reveals the secret, it’s not a mystery anymore. But Boyer and Hall argue that this isn’t the case. A biblical mystery isn’t just a secret that becomes fully known once the information is given. A biblical mystery remains mysterious even after we find out about it. God has revealed the mysteries of the resurrection (1 Cor. 15:51), the hardening of Israel (Rom. 11:15), and the hope of glory (Col. 1:27), yet all of these continue to transcend our understanding of them even after they are revealed.

So Boyer and Hall argue that a key difference between the first and second kinds of mystery: “an investigative mystery revolves very intentionally around what is unknown, whereas a revelational mystery revolves around what is known” (p. 6).

3. Mystery as Quantitative Inexhaustibility

With this kind of mystery we’re talking about something so amazingly complex that we cannot possibly hope to understand everything. Like the investigative mystery, the knowledge is knowable. But here the problem isn’t with a lack of information but a surplus. There’s just too much information for the mind to process.

For example, my cell phone is a mystery to me in this sense. The information exists, it’s just too complicated for me to understand. Of course, to a cell phone expert, cell phones aren’t all that mysterious. But something else will be. For finite beings an an amazingly complex universe, something will always be mysterious in this sense. There’s just too much information.

But Boyer and Hall don’t think this one is adequate for the mysteries of God’s being either. After all, do we really want to think of God as mysterious in the same way as a cell phone? Is it just that there are too many bits of information for any single person to store in their head, or is there something about God that transcends even this kind of mystery?

4. Mystery as Nonrational Opaqueness

Here we’re talking about a mystery that is more than quantitative (amount of knowledge). This is a qualitative mystery. There’s something unique about the kind of knowledge involved so that it “seems to resist rational, analytical investigation” (p. 8). The mystery just doesn’t seem knowable, at least in the ways that we usually use the term “know.”

The best example here is the kind of knowledge that we have of persons. If I somehow managed to tell you everything that I know about my wife so that you understood all of that information perfectly, you still wouldn’t know her. You’d know a lot of facts about her, but personal knowledge is qualitatively different. It cannot be captured or expressed rationally. I could write poems or paint pictures to try and convey the sense of her, but even that would only wave a hand in her direction.

This category has always been a popular one for understanding divine mysteries. Here we arrive at a definition that moves mystery beyond the realm of human knowledge, acknowledging that God is the kind of being who will always transcend human knowledge, not just because there are too many bits of information, but because the kind of knowledge involved is cannot be quantified or objectified. Ultimately, knowing God is non-rational.

But Boyer and Hall point out some good reasons for being careful with this one as well. First, by making knowledge of God completely non-rational, it undermines the theological task itself. Our theological affirmations end up having almost nothing to do with God himself. And as popular as this non-rational view of theology might be in some strands of contemporary theology, they point out that it is radically out of step with most of the church historically:

to question the legitimacy of the theological enterprise in this wholesale fashion would put us seriously out of step with the church throughout the ages….In other words, it is not as though rationally cogent doctrine were one thing and the mystery of God were another. The two seem to interpenetrate in ways that construing the mystery of God only in the facultative sense cannot account for. (p. 9)

Second, this approach actually ends up undermining the nature of mystery. Every experience that I have is mysterious in this sense given that personal experience is also impossible to quantify objectively. How do you describe the beauty of a rainbow, the taste of coffee, or the pain of stubbing your toe? Since all experience transcends knowledge in this sense, though, the knowledge of God ends up being no more mysterious than a sore toe. Is that really where we want to go with the knowledge of God?

Finally, they’re concerned that this approach ends up suggesting that since our intellectual faculty is insufficient for knowing God in this way, there must be some other faculty (maybe the affections) that is more adequate to the task. But for a transcendent God, no human faculty could possibly be adequate to knowing him fully. If that’s the case, then, although personal knowledge and experiential knowledge are interesting analogies for knowing God, they too fall short of what we’re looking for.

5. A Dimensional Mystery

The final definition of course presents their own understanding of a divine mystery. And here they appeal to the way that dimensions affect knowledge. For example, imagine a two-dimensional being looking at a circle. Our 2D friend could say all kinds of interesting things about the circle (circumference, radius, etc.). All of which would be completely true.

Now suppose that the circle is actually just one end of a cylinder. Existing in a third dimension, the cylinder itself is a complete mystery to Mr. 2D. I could tell him about it, and he may even choose in faith to believe me about things that completely transcend his rational horizons (e.g. volume), but he wouldn’t really understand the cylinder. He can’t.

The key with a dimensional mystery, though, is that the mystery “transcends but does not invalidate rational exploration.” With our example, remember that Mr. 2D does know some things about the cylinder because he knows something about the circle at one end of the cylinder. And when the truth of the cylinder is revealed to him, those things are still true. The transcendent mystery puts that knowledge in a new context, helping him see that they are just part of a greater whole, but it doesn’t invalidate those truths. And this is true even if Mr. 2D doesn’t see how it’s possible. For him, ideas like volume seem completely inconsistent with what he knows of the universe. It seems irrational. But it’s not.

Boyer and Hall argue that knowledge of God is a lot like this. Even though God’s being radically transcends our knowledge, it doesn’t invalidate what we do know. He exists in dimensions we cannot conceive, but he also exists right where we are. He transcends, but he also reveals.


So what is a mystery in theology? To some degree, it’s a combination of many of these definitions. Some theological truths may well be mysterious in a quantifiable sense. For example, in the free will debate, a lot of the challenges stem from the fact that the human brain is amazingly complex, transcending our ability to understand precisely how physical processes in the brain are involved in supposedly free choices. It may well be that the information is all there and it just transcends our limited abilities to process all of it.

And knowledge of God is certainly mysterious in the sense that it involves experiential knowledge of a personal being. Some of our knowledge of God will consequently be of the non-rational sort that cannot be captured in theological affirmations.

But I like the argument that much of the mystery stems from the fact that God’s being simply transcends our reality. He does reveal himself to us, and we strive to understand that revelation faithfully. But even in revelation the mystery remains mystery because we only see one end of the cylinder. And it gives us a great picture of heaven. Even in the eschaton, God will remain mysteriously transcendent, eternally unveiling new dimensions of himself that radically reorient what we already knew. That’s an eternity I can get excited about.




  1. Lane says

    I always like the “Dimensional Mystery” analogy of the wave – particle duality of light. In some circumstances light (actually all particles) acts like a wave, yet in other circumstances it acts like a particle. However, in classical physics a particle and wave would be contradictory states and could not explain this seemingly paradoxical phenomena. There was something missing from our understanding that would eliminate the paradox, even though classical physics could seemingly explained either nature quite well.


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