Defeat of the Will part 1
Christianity is so absurd that it may seem that Christians simply have no control over their beliefs. But most people have the willpower to stop believing- all you need to do is realize how immoral and absurd it all is, and decide to stop. Religion is an addiction, like alcoholism or gambling. If you become disgusted with your own behaviour and decide to stop, there is a good chance you will succeed.
The question of will seems a priori to be pretty simple: Christianity claims we must surrender our will to the will of God, and we claim the opposite. Pretty simple on paper, but it doesn't work that way.
For one thing, surrendering our will is impossible. Remember that part of the human will is the capacity for moral judgment. Obviously, children brainwashed by their parents to believe in God did not use their moral judgment to get to that point. But any adult who is a Christian, or becomes a Christian, uses his moral judgment in maintaining his belief. At any point in time such a person is free to investigate his religion for himself and find out the immoralities and absurdities of its worldview or basic doctrines.
This means that some human judgment always remains in the submission to any belief system, even if only apathy in not finding out the truth. Indeed, if submission of the will was possible, then why would religious believers always experience so much doubt and falling-out? How could Christians deconvert? One may argue that they were not "true Christians", but this accusation remains a rationalization. If the only way to distinguish between a "true Christian" and a "false Christian" is that the latter does things that the believer disapproves of, then it is merely personal opinion.
Also, I'd wager that even fanatic Christians use their own secular judgment on most occasions. While they may constantly praise God and speak Christianese, they make most decisions on the basis of the facts of reality and then rationalize them with more Christianese later (such as "Help yourself and God will help you", which is not Biblical, or "love your neighbour as yourself", using their own unbiblical definition of "love"). Their rationalizations are ways for them to get away with their good and evil actions which are without Biblical foundation.
Finally, being a Christian still requires fundamental judgment - to subvert your will to Christianity demands that you know what Christianity is! History proves that this is no trivial task. It took a long time for Christian leaders to figure out what their religion was, and since then many schisms (and millions of deaths) have demonstrated that there is still no unity of thought.
When the Christian uses whatever epistemic method he thinks he's using- reading the Bible, receiving "divine revelation", listening to his redneck pastor- he is still using his judgment to determine whether those propositions come from God, Satan, or whatever other spooky sources there might be. And the fact remains that there is no way for the Christian to make such judgment rationally. As I've pointed out before, if we accept the premise that an infinitely powerful being exists, then it could very well be that the believer is deluded in believing that this being is communicating truth to him, when in fact the being is manipulating or controlling that person. This is a variant of Descartes' Evil Demon argument applied specifically to theology.
More in part 2.