The non-regenerate man seeks by all means to “keep under” this remnant of a true theistic interpretation that lingers in his mind. His real interpretative principle, now that he is a covenant-breaker, is that of himself as ultimate and of impersonal laws as ultimate. It is he himself as ultimate, by means of laws of logic that operate independently of God, who determines what is possible and probable. To the extent, then, that he proceeds self-consciously from his own principle of interpretation, he holds the very existence of God, and of the creation of the universe, to be not merely improbable, but impossible. In doing so he sins, to be sure, against his better knowledge. He sins against that which is hidden deep down in his own consciousness. And it is well that we should appeal to this fact. But in order to appeal to this fact we must use all caution not to obscure this fact. And obscure it we do if we speak of the “common consciousness” of man without distinguishing clearly between what is hidden deep down in the mind of natural man as the revelation and knowledge of God within him and what, in rejecting God, he has virtually adopted as being his final interpretative principle.
– Cornelius Van Til, An Introduction to Systematic Theology p.82-83
We have already indicated that the best apologetic defense will invariably be made by him who knows the system of truth of Scripture best. The fight between Christianity and non-Christianity is, in modern times, no piece-meal affair. It is the life and death struggle between two mutually opposed life and world-views. The non-Christian attack often comes to us on matters of historical, or other, detail. It comes to us in the form of objections to certain teachings of Scripture, say, with respect to creation, etc. It may seem to be simply a matter of asking what the facts have been. Back of this detailed attack, however, is the constant assumption of the non-Christian metaphysics of the correlativity of God and man. He who has not been trained in systematic theology will often be at a loss as to how to meet these attacks. He may be quite proficient in warding off the attack as far as details are concerned, but he will forever have to be afraid of new attacks as long as he has never removed the foundation from the enemy’s position.
– Cornelius Van Til, An Introduction to Systematic Theology p.23-24
Christian and Non-Christian Views:
Both Christians and non-Christians make presuppositions about the nature of reality.
a. The Christian presupposes the self-contained God and his plan for the universe as back of all things and therewith the absolute distinction between Creator and creation.
b. The non-Christian presupposes “Chaos and Old Night,” or the self-existence of matter in some sense.
– Cornelius Van Til, The Reformed Pastor and Modern Thought.
(Variations in The Defense of the Faith p.304, and Jerusalem and Athens p.19)