When therefore we examine the various epistemological views with regard to their “objectivity,” we are interested most of all in knowing whether or not these views have sought the knowledge of an object by placing it into its right relation with the self-conscious God. The other questions are interesting enough in themselves but are comparatively speaking not of great importance. Even if one were not anxious about the truth of the matter, it ought still to be plain to him that there can be no more fundamental question in epistemology than the question whether or not facts can be known without reference to God.
Suppose for argument’s sake that there is such a God. And surely the possibility of it anybody ought to be willing to grant unless he has proved the impossibility of God’s existence. Suppose then the existence of God. Then it would be a fact that every fact would be known truly only with reference to him. If then one did not place a fact into relation with God, he would be in error about the fact under investigation. Or suppose that one would just begin his investigations as a scientist, without even asking whether or not it is necessary to make reference to such a God in his investigations, such a one would be in constant and in fundamental ignorance all the while. And this ignorance would be culpable ignorance, since it is God who gives him life and all good things. It ought to be obvious then that one should settle for himself this most fundamental of all epistemological questions, whether or not God exists. Christ says that as the Son of God, he will come to judge and condemn all those who have not come to the Father by him.
– Cornelius Van Til, A Survey of Christian Epistemology p.4