Men in general are, therefore, truth suppressors. They are not those who are first of all without knowledge of the truth. They are indeed such, if one thinks of the knowledge that must come from Scripture. But they are first of all truth possessors, or truth-knowers, who have, by sinning, become truth suppressors. Having taken to themselves the right to define the nature of God and of themselves, they have mingled the idea of their new god with that of the God they know by virtue of their creation. In their natural theology, that is, in what, as sinful men, they set forth as their view about God, they never state the truth without adulteration. They do not completely succeed in suppressing the truth, but they never assert the truth without an overwhelming admixture of error. The god of the philosophers is never their Creator and the Creator of the universe. He is always of necessity bound up with his creation. Hence sinful unregenerate men never worship the true God as they ought. In practice they do not know him because when they think of him they, of necessity, think falsely of him; they always degrade him to the level of the creature.
– Cornelius Van Til, The Reformed Pastor and Modern Thought.