When apologists talk about knowledge, they are describing what is known as “epistemology.” Britannica defines epistemology as “the philosophical study of the nature, origin, and limits of human knowledge”. The term derives from the Greek epistēmē (“knowledge”) and logos (“reason”), and is sometimes referred to as the theory of knowledge. It is one of the three disciplines in Christian philosophy, the other two being metaphysics (the nature of reality) and ethics.

How do we know what we know? Epistemology seeks to answer that question.

Knowledge is justified true belief. Knowledge must be both true and warranted (justified.) For example, what if I say that “it’s raining in Moscow”? If I make that statement because I just watched a weather report on Moscow, or I’m on the phone with a friend who is in Moscow and who just told me that it’s raining there . . . I have warrant to believe that is’ true. I have expressed knowledge. But if I make the statement and have no idea if it’s really raining in Moscow, that does not qualify as knowledge, even if it’s true because I have no warrant to believe it.

For knowledge to be true, it must be rooted in metaphysics (reality.) When we talk about reality, we are describing truth. Truth accords with reality. How do we know something is true? We know trutb because it is reflected in reality. How do I know that two hydrogen atoms combine with an oxygen atom to produce water? I know it because it is reality. We must be careful to distinguish knowledge from opinion. Opinion is not knowledge. When we present opinion as knowledge, we become a rudderless ship adrift on cultural currents. I may hold the opinion that human sex is interchangeable, that man can become a woman and vice-versa. But it is not knowledge because it is not true; in fact, it is biologically impossible for a man to become a woman. If our knowledge is not based in reality, we end up in nihilistic Wonderland where anything, no matter how absurd, is regarded true.

There are two extremes (neither of which we want to hold) when it comes to the extent of our knowledge: either (1) humans can know everything, or (2) humans can’t know anything. Extreme (1) is the view arising out of the Enlightenment. Extreme (2) ultimately means there is no such thing as absolute truth. Neither extreme is correct and both are dangerous; unfortunately we encounter both extremes in today’s increasingly chaotic culture.

How do we know if a specific worldview (i.e., its’ understanding of reality) is correct? By testing it to see if it is coherent and consistent with truth. Does it have explanatory power? Is it practically relevant? Does it have empirical adequacy with demonstrable, observable facts? What happens if we follow it to its logical conclusion? What is ultimate reality in the worldview? If the worldview’s answer to ultimate reality is something other than God, it has a fatal flaw. As the Architect of all reality, God IS ultimate reality.

In this fallen world, the Noetic effects of sin (the effect of sin on the mind) can hamper our knowledge. Even in the next life when we are finally free of sin, we will still be limited in our knowledge by our finite nature. Some Christians incorrectly understand 1 Cor 13:12 (For now we see only a reflection as in a mirror; then we shall see face to face. Now I know in part; then I shall know fully, even as I am fully known) to mean they will have perfect, complete knowledge in Heaven. It is impossible for a finite mind, even when glorifed, to know everything. What 1 Cor 13:12 means when it says we “shall know fully” is that all our knowledge will be correct free of the noetic effect of sin. But we will never know everything regarding an infinite God. In other words, we can never exhaustively know God in his fullness, but we can correctly know him. For all eternity, we will grow in our knowledge of God who is infinite in his perfections.