This essay is part of a series considering various aspects of philosophy and apologetics. Shawn Langley is a Research Fellow with the BibleMesh Institute.
How Do We Know God Exists?
Few questions matter more to the overlap of philosophy and theology than God’s existence. And few questions matter more to God’s existence than how we can even begin to know such a thing in the first place.
To answer how it is we can know God exists, we need to define a little more carefully what it is we are asking. What does someone mean when they ask, How do you know that God exists? How do you know something? Are they asking us for some measure of logical consistency among all our specific beliefs? Are they asking us to demonstrate a sense of inner peace or some other subjective feeling? Are they asking us to show them some objective certainty to judge our claims by? What is it we want to know when we ask about what we know?
This actually breaks the question of God’s existence into two more basic questions: (1) how does knowledge work in general, and (2) how does it relate to God in particular?
How Does Knowledge Work?
To understand how questions of knowledge work, we need to distinguish between the sources of knowledge on the one hand, and the success of knowledge on the other. A source of knowledge is simply a part of our cognitive workings that helps us know what is going on in and around us. Consider two of the more recognizable sources of knowledge: perception and testimony. How do we know, for instance, what the table in our office is made of? Well, we normally just look at it and come to believe that it appears an awful lot like wood. And so the way we come to know most of the things we are surrounded by here in life is simply through perceiving them.
Similarly for testimony: how do we know what someone’s name is? Unless they are unusually mysterious, they typically just tell us. Every once in a while, you’ll hear someone say, “You look like a so-and-so!” But whatever that means, perception is not the typical source of our knowledge when it comes to names. This is the same thing with our knowledge of the past. We weren’t there, so we rely on the testimony of someone like Moses or Matthew as the source of our knowledge.
With these sources of knowledge in mind, let’s think about the success of knowledge. The reason we must distinguish between merely a source of knowledge and whether or not it is successful is, simply put, because we can be wrong.
We said the table in our office was wood because it looked a lot like wood. But what if someone came in and told us it was really just cheap but convincing plastic made to resemble wood. Now we have a problem in our understanding. Our source of knowledge seems like it might not have been successful.
Or, say you meet someone who tells you all about their innovative, world-changing company and its exciting investment potential. But then you pick up a newspaper and see your new friend’s picture next to a headline about fraudulent businesses swindling people out of their hard-earned money. You might start to question whether their testimony was a successful source of knowledge.
In essence, sources like perception and testimony provide us with the raw data of the world we live in. Our responsibility as thinkers is to interpret that data and determine as best we can how successfully it reflects the way things are. Often, there will be little that conflicts with our most basic understanding of what the data probably means, and this itself is a big part of how our minds are meant to work. But every once in a while we run into competing accounts of what the data is telling us, especially when it comes to the deepest matters of life.
Knowledge and the Existence of God
With the question of God’s existence, this distinction between the source of knowledge and the success of knowledge provides us with two possibilities for how we might approach an answer.
First, we could move from the sources to their success, trying to show that what we perceive, for example, can only really succeed after we have incorporated God into our understanding of those perceptions. We perceive order and creativity and beauty, so we might say our perception of these things leads most reasonably to God.
In other words, if we remove God from our interpretive framework, it becomes difficult to reconcile this order and creativity and beauty of our perceptions with other parts of the framework. An alternative perspective to theism, such as naturalistic materialism, might have an explanation for aspects of the physical world that we encounter, but it offers little by way of insight when it comes to our perception of joy in the face of pain or self-sacrificing love. Perception as a source of knowledge, were we to take God away, would fail to find success on this line of reasoning.
This is one possibility, and it is the one most familiar to discussions of God’s existence. But the church throughout its history has also attempted to answer the question from the opposite direction. That is, rather than trying to show how any specific source of knowledge points to God, we could try to show how the possibility of successful knowledge itself demonstrates his existence.
This may sound paradoxical at first, but it is actually how we reason all the time. Imagine if you had to confirm every instance of perception or testimony whenever you used them as sources of knowledge to determine whether they were successful. What if you couldn’t believe anything anyone ever said to you until you had exhausted any conceivable possibility of doubt?
Thankfully, our minds are constructed to operate on the assumption that our sources of knowledge are successful under normal circumstances. And this has major implications for how we think of God’s existence.
To see why this is the case and why it is so important, consider what is required for these sources of knowledge to work the way we assume they do. Why do you set your alarm with confidence that time persists from one day to another? Why do basic moral judgments not change when you go across the street or across the ocean or across centuries and millennia? Why does the relative value of numbers never change, so that somedays the richest people in the world are the ones with the smallest numerical amount of money instead of the largest?
What all these questions underscore is that the success of our knowledge is dependent on certain universal and unalterable factors being the case prior to any possibility of knowing. Why do you set your alarm? Because the natural world does not change. Why do you trust moral judgments across time and space? Because the moral world does not change. Why do you (perhaps regrettably) accept the relative value of money? Because the invisible world of concepts like numbers does not change.
And then we ask, Why does the natural and moral and invisible conceptual world never change, giving rise to the possible success of our sources of knowledge? Because God exists. These three words can often offend in their simplicity, but any reasonable attempt to define knowledge apart from God is ultimately betrayed either by destroying the possibility of knowing altogether or sneaking in a substitute to fill the void left by his alleged absence.
What would keep a mindless cosmos in perfect order other than a perfectly ordered Mind? What would uphold an ever-present moral law other than an ever-present moral Lawgiver? What would maintain the invisible and infinite validity of concepts other than the invisible and infinite Creator? We know God exists not merely because we could not otherwise answer the questions of knowledge, but more so because without him we could not even ask them.
Shawn Langley
Shawn Langley is also a Research Fellow at the Kirby Laing Centre for Public Theology in Cambridge, England. His writing focuses on the relationship between philosophy & theology, particularly the way epistemological questions shape and are shaped by biblical interpretation.