The Problem of Believing What You Want

*EDIT: upon rereading this post, I realize I have left out a critical point.  Fortunately, the point pretty much makes itself when you read the definition of confirmation bias.  Ah, the perils of instantaneous publishing...*

I have a confession to make: I desperately want to believe in Christianity.  And it's not just about the girl anymore.

The more I devote myself to figuring out what I believe, the more I realize how purposeless life is without God.  Without something more to believe in, the best we can possibly do is jump from one fleeting happiness to another.  And that's only if we can achieve the cognitive dissonance necessary to ignore the fact that none of it matters (I will admit here that this may not be a problem for everyone; some people may be perfectly satisfied with a life of happiness that has no grander meaning.  I am not one of those people)

But there's a problem.  As much as I want to believe, I still need a reason to.

If the truth is uncertain, the natural tendency is to believe what you want to be true.  And for the most part, that's fine.  That's a reasonable way to live your life- in fact, it's healthy.  Only a truly cynical human being goes through life expecting the worst without any reason to.  But what happens when what you want changes?

I believed in Christianity for a very long time.  I was no more or less rational then than I am now.  But it wasn't until I looked at it with unbiased eyes- until I admitted that what I wanted more than belief was truth- that my doubts overcame my faith.  In the end, I had nothing with which to fight those doubts.  I walked away from Christianity because when I looked at it without the desperate desire to believe, I didn't believe it.

Let us stop here for another honesty break- there's no such thing as unbiased eyes.  Bias is a frustrating beast, in that you can rarely recognize it within yourself.  I have no doubt that I was biased in a hundred different directions by a thousand competing forces when I walked away, most of which still remain unknown to me.  However, I can say with confidence that I was, when I believed, most definitely biased towards belief, and that my acceptance of Christianity was in no small part  (though I will not go so far as to say entirely) based upon this bias.

If Christianity seems plausible but uncertain to me now, then what's to stop me from doing exactly what I did before and walking away at some point in the future when I don't desperately want it to be true?  If I am ever to believe in Christianity again, then I need an answer to the question: "What's different this time around?"