To say that Scripture testifies to itself and therefore identifies itself is to imply that it also identifies every fact in the world. That is to say the God of which the Scriptures speak is the God who makes the facts to be what they are. There can therefore be no fact which is ultimately out of accord with the system of truth set forth in Scripture. Every fact in the universe is what it is just because of the place that it has in this system.
Moreover, to say that every fact in the world is what it is because of its place in the system of truth set forth in Scripture, is to establish the legitimacy of the Christian principle of discontinuity. The system of truth set forth in Scripture cannot be fully understood by the creature. The point here is not merely that creatures who are sinners are unwilling to believe the truth. The point is further that man as finite cannot understand God his Maker in an exhaustive manner. As he cannot understand God exhaustively, so he cannot understand anything related to God in an exhaustive way, for to understand it we would have to penetrate its relation to God and to penetrate that relation we would have to understand God exhaustively.
– Cornelius Van Til, A Christian Theory of Knowledge p.35-36