Epistemology, or the theory of knowledge, is that branch of philosophy that is concerned with the nature and scope of knowledge, its presuppositions and basis, and the general reliability of claims to knowledge. What is knowledge? What does it mean to know? Are there different types of knowledge? Is my knowledge of an inanimate object the same as my knowledge of an abstract concept? What about my knowledge of other human beings? From whence does knowledge come? What is the origin and source of knowledge? In the Ptolemaic system, as in the cosmogony of the Bible, man was assigned a central position in the universe, from which position he was ousted by Copernicus. Polanyi is only partly correct. Man has never really occupied the central position of knowledge in the universe. That position has always only been occupied by God. However, in his original condition, man could have a much greater degree of confidence in his knowledge of the universe because his interpretation of the data that he processed was unaffected by sin. As a result of the fall however, man now finds himself in epistemic pandemonium. Man’s interpretation of the data and the manner in which he reasons about human experience is dreadfully prejudiced by a sinful nature that is contrary to God at its very core. Can human knowledge be salvaged? How can man make account for the intelligibility of the human experience we call “knowing?” The purpose of this short article is to provide a very brief overview, a curt introduction if you will, of the subject of epistemology and to assist you, the busy Christian, in recognizing the radical difference that exists between the Christian view of knowledge and the many competing non-Christian views of knowledge. For the sake of space, I will only address the largest of the large stones in this particular stream.
There are two basic kinds of knowledge that philosophers commonly discuss in the literature. Something is said to be known a posteriori if it is known on the basis of human experience. On the other hand, to know something apart from experience, for example, the laws of logic, my knowledge is said to be a priori. For the average person, it seems uncontroversial to say that human beings experience knowledge. But for the philosopher, it is anything but uncontroversial. Any Christian interested in confronting men with the gospel of Jesus Christ will eventually and sooner than later, have to deal with the question, “How does man account for the intelligibility of the phenomenon of human knowledge?” This naturally leads to the challenging question, “How do you know that Christianity is true?” The Christian response to the question of genuine knowledge is fundamentally opposed to its many non-Christian options. The purpose of this article is to provide a constructive summary of a distinctly Christian epistemology. Before moving into that construction, a word should be said about two of the most common epistemologies embraced by most people in our culture.
Rationalism is the belief that human knowledge comes through the mind, or human reason. The underpinning of human knowledge is said to be the human mind. Take for example the idea of Euclidean triangles. All Euclidean triangles have interior angles that total 180 degrees. How do we respond if someone asks us how we know that this is the case? Do we say we know it by observation, like we know that crows are black? By definition a Euclidean triangle has interior angles that total 180 degrees or it is not a Euclidean triangle. Once we understand the nature of the Euclidean triable, our knowledge of it seems innate, immediate. We feel no need to go looking for a Euclidean triangle that may NOT meet the criteria. We know intuitively it seems that one does not exist and we know this with certainty.
On the other hand, empiricism holds that human knowledge is experiential in nature. All knowledge is the product of sensory data. That is to say that knowledge has to be empirical in nature, coming through the senses, in order for it to count as knowledge. For example, I know that all crows are black birds. If it is a crow, I know that it is a bird, and I know that it is black. I know a posteriori that all crows are black. That is to say, I know by observation, the sense of sight, that all crows are black. Someone might say, well, you only know that the crows that you have observed are black but have you observed all crows? That is sort of the point. One theory of non-Christian epistemology is that all knowledge is of this sort; knowledge arises out of experience. Empiricism is the theory of knowledge that underlies modern science. Empiricism not only contradicts Christian teaching, it inevitable collapses when subjected to critical scrutiny. This is not to say that no knowledge comes through the senses. It is only to say that knowledge is not limited to sense experience alone. Moreover, sense perceptions are subject to individual interpretation. It is at the level of worldview that basic presuppositions for the building blocks of interpretation come into play.
Contrary to rationalism and empiricism, two very common theories that attempt to explain how human knowledge is possible apart from knowledge of God, the Bible informs us that human knowledge is revelational in nature, and as such, is entirely dependent on God. Empiricism and rationalism view man as autonomous and therefore, fully capable of properly interpreting the nature of the world in which he finds himself. The Greek philosopher Protagoras believed that “man is the measure of all things.” This is the sine qua non of unbelieving thought. This is the fundamental difference between a Christian view of knowledge and a non-Christian view of knowledge. Christians must insist from the very beginning that all human knowledge is revelational in nature, and is therefore utterly dependent on God. When God created the world, and placed Adam in the garden, he had to transfer knowledge to Adam. When we think about how knowledge starts, we are left with the impossible task of explaining how knowledge can arise from no knowledge. It is very similar to something extended in space and time arising from nothing. The human mind cannot comprehend it. The idea that a blank slate could ever become a rational being organizing complex input from sensory data, categorizing it correctly is a nonstarter. How could one even know what data is? Where would the categories come from to begin with? Without knowledge, knowledge is impossible. Knowledge is not something that is capable of appearing from nothing. It is impossible for knowledge to have not existed at some point in time. From no knowledge, no knowledge comes!
According to the Christian worldview, God created the world and all things in it. Genesis 1:1, “In the beginning God created the heavens and the earth.” Not only would such an act require a very powerful being, it would require a very knowledgeable one as well. We do not have to look past the metaphysical claims of Genesis 1:1 to understand the source of knowledge. It is God. God, being a being, or better, a person who possesses knowledge, created human beings in His image, like him. Human knowledge then has its source in God. God created human beings with the ability to know, and understand their world as well as their creator. From this we can conclude that all genuine knowledge then is at bottom, revelational in nature. And this is true for a priori and a posteriori knowledge. God has revealed himself and his works of creation to man from the very beginning according to Romans 1:19-21. Romans 2:14-15 even goes so far as to tell us that God has made it impossible for man not to know something about morality along with his knowledge of the created world. This knowledge is referred to in Christian theism as natural revelation, or natural knowledge of God.
But even natural knowledge is revelational in nature. It is given to man, written in man innately. Not only that wired into man is his natural capacities to learn about his environment. Without God, man cannot know anything about his world or about himself. Not only this, there is another kind of knowledge. This is a more accurate knowledge that has as its mechanism the biblical idea of faith. Faith-enabled knowledge is the restoration of man to his prior ability to know himself, his environment, and his Creator more accurately. Redemption applies to the whole person. The Christian’s knowledge is redeemed knowledge. Hebrews 11:3 tells us that our understanding of how the universe came into existence is by faith. We know and understand that the world was created by God through the vehicle of faith. Faith produces genuine knowledge. It is a supernatural gift of God that is, as some might call it, an epistemological game-changer. Christians do not come to know God through rational arguments and empirical evidence as a result of autonomous human inquiries and examination. This is a method of reasoning that is toxic to the Christian faith. It is a product of enlightenment philosophies, not biblical theology. Christians come to true knowledge by the regeneration of the Holy Spirit, Who, in the process, grants to believers the gift of faith. It is a result of God’s amazing grace!
Evangelism and apologetics done correctly acknowledges that Christian converts are not made by clever or sophisticated philosophical arguments using logic and empirical evidence. Christian converts are not made because your message is fashioned in just the right way so as not to offend wicked sinners. Christian converts are made by the Holy Spirit through the power of the Word of Christ preached and proclaimed faithfully by those who have faith in God’s ability to resurrect the dead sinner. Even the most reformed among us very often are tempted to tamper with this process, thinking, in moments of weak faith, that God needs our help. He does not. I close this article on epistemology, as strangely as it might seem to some, with the words of Paul: and my speech and my message were not in plausible words of wisdom, but in demonstration of the Spirit and of power, so that your faith might not rest in the wisdom of men but in the power of God. 
 Edwards, Paul. The Encyclopedia of Philosophy, Vol. 3 and 4, (MacMillan Publishing Co. Inc. & The Free Press, NY, NY), 8-9.
 Michael Polanyi, Personal Knowledge: Towards a Post-Critical Philosophy, corr. ed. (Chicago: University of Chicago Press, 1962), 3.
 The Holy Bible: English Standard Version (Wheaton: Standard Bible Society, 2016), 1 Co 2:4–5.