“So then the whole argument between Christian theistic and anti-theistic epistemology stands before us. There is much that might still be discussed. It is possible to enter upon a profitable discussion of many details. However, it was our purpose to speak of only the most important matters.
These most important matters were somewhat as follows: first of all, we note the necessity of seeing clearly that Christianity and theism are intricately interwoven. If one is really a theist he cannot stop short of being a Christian, and Christianity cannot build upon any foundation but that of a sound biblical theism. Accordingly, the argument must constantly be for Christian theism as a whole. We cannot separate, except for the sake of emphasis, between an argument for theism and an argument for Christianity. The absoluteness of God and the inspiration of the Bible are involved in one another and one cannot defend the one without defending the other.
In the second place, this whole Christian theistic position must be presented not as something just a little or as a great deal better than other positions, but must be presented as the only system of thought that does not destroy human experience to a meaningless something. This is in accord with the teaching of the Bible that those who do not accept Christ are lost. Accordingly, if Christian theism is defensible at all it must be defensible in this way. And if it is not defensible in this way it is not defensible in any other way, because any other way of defense reduces the uniqueness of Christianity at once. The question is one of “this or nothing.”
The argument in favor of Christian theism must therefore seek to prove that if one is not a Christian theist he knows nothing at all as he ought to know anything. The difference is not that all men alike know certain things about the finite universe and that some claim some additional knowledge, while the others do not. On the contrary, the Christian theist must claim that he alone has true knowledge about cows and chickens as well as about God. He does this in no spirit of conceit, because it is a gift of God’s grace. Nor does he deny that there is knowledge after a fashion that enables the non-theist to get along after a fashion in the world. This is the gift of God’s common grace, and therefore does not change the absoluteness of the distinction made about the knowledge and the ignorance of the theist and the non-theist respectively.
The method of argumentation will accord with the general position taken so far. It will seek to show that antitheistic knowledge is self-contradictory on its own ground, and that its conception of contradiction even presupposes the truth of Christian theism. It must be the method of the impossibility of the contrary, or that of the destruction of the enemy. It must show that univocal reasoning is self-destructive.
Meanwhile, Christian theism has the solemn duty to implicate itself ever more deeply into the truth of God as it is revealed in nature and in Scripture till the end of time. It must become ever more explicit in the formulation of what it sees to be the truth in order that it may not lose its identity as time goes on, but the rather gain in its distinctiveness and therefore in its testimony to the world. Magna est Veritas et praevalebit.”
(Van Til, A Survey of Christian Epistemology, 190-191)