“It thus appears that we must take the Bible, its conception of sin, its conception of Christ, and its conception of God and all that is involved in these concepts together, or take none of them. So also it makes very little difference whether we begin with the notion of an absolute God or with the notion of an absolute Bible. The one is derived from the other. They are together involved in the Christian view of life. Hence we defend all or we defend none. Only one absolute is possible, and only one absolute can speak to us. Hence it must always be the same voice of the same absolute, even though he seems to speak to us at different places. The Bible must be true because it alone speaks of an absolute God. And equally true is it that we believe in an absolute God because the Bible tells us of one.
And this brings up the point of circular reasoning. The charge is constantly made that if matters stand thus with Christianity, it has written its own death warrant as far as intelligent men are concerned. Who wishes to make such a simple blunder in elementary logic, as to say that we believe something to be true because it is in the Bible? Our answer to this is briefly that we prefer to reason in a circle to not reasoning at all. We hold it to be true that circular reasoning is the only reasoning that is possible to finite man. The method of implication as outlined above is circular reasoning. Or we may call it spiral reasoning. We must go round and round a thing to see more of its dimensions and to know more about it, in general, unless we are larger than that which we are investigating. Unless we are larger than God we cannot reason about him any other way, than by a transcendental or circular argument. The refusal to admit the necessity of circular reasoning is itself an evident token of opposition to Christianity. Reasoning in a vicious circle is the only alternative to reasoning in a circle as discussed above.”
(Van Til, A Survey of Christian Epistemology)