Author Etienne Gilson wrote an excellent history of philosophy titled The Unity of Philosophical Experience. In it he speaks about philosopher Rene Descartes, who was trying to use logic and reason to their very limits, trying to prove every single thing by reason. Descartes was trying to use reason to not just prove the unknown, but to also prove the obvious. Gilson says the following of Descartes use of reason:
He was forbidden by his own principles to take [the existence of the material world] as an established fact. Like the rest, it was in need of being proved, and it could not have been proved at an earlier stage of the deduction. The mind first, God next, then and only then, the external world. Such was the order. Why should Descartes have worried about it? He himself believed in the existence of matter, and he knew that everyone else would keep on believing in it anyway. Besides, was he not about to prove it? The only difference would be that men, henceforward, would know it instead of believing it, and for a philosopher at least, that was the proper thing to do. Having thus made up his mind, Descartes looked about for a proper starting point toward that new goal. (p.144)
Now we must remember that Descartes was no dummy, nor was he a flaming religionist. His method was to doubt all things, and then use this doubt to prove things. He is widely held to be the first of the modern thinkers.
What strikes me as being interesting is the way Descartes approached his problem. He made up his mind how things were to be, how the conclusion was to come out; he even kew everyone agreed with him already. He then set out to prove what he already knew.
It strikes me the same is going on today in the camps of both Christians and atheists. We have our minds made up, we already know the answer, and we set out to reason through a proof. As Walter Martin once said, when most people think, they are not really thinking, they are merely rearranging their prejudices.
The difference to me is that most Christians are reasoning this way while thinking that they are not using reason, and most atheists have convinced themselves that they are using sound reason, when all the while their logic is just as full of unproved assumptions and circular processes as Descartes.
The atheists are quick to point out the absurdities of the Christians. It is getting easier and easier to show the glaring flaws of the modern atheist heroes who worship logic and reason, but do not seem to have turned it on their own assumptions very well at all. They seem to be in a very similar situation as our friend Descartes.