At the risk of alienating everyone :-), I'm going to make what seems to me a statement of obvious truth:
It is neither unreasonable nor foolish to believe in God, AND it is neither unreasonable nor foolish to be skeptical about God's existence.
On the face of it, this perhaps seems like a contradictory statement. How can it be reasonable both to believe in God and to be skeptical of God's existence? Well, I don't want to get onto a rabbit trail right off the bat, but it all depends on how one defines 'reasonable'. And I am not defining that word in purely rational terms; in other words, I don't equate 'reasonable' with 'Reason'. Something can be perfectly reasonable even if it doesn't fit neatly into a logical equation or a statement of fact.
For instance, even if I have experienced a terrible break in a friendship due to conflict of some kind, it may nevertheless be reasonable for me to expect that, given the circumstances, if I seek to mend the friendship, it will be restored. At the same time, however, it may also be reasonable for me to expect that, given the circumstances, my friend will not want to mend the friendship and it will not be restored. I can't know for sure what will happen, and there are reasonable arguments both ways.
Now, this might make it sound as though I am appealing to experience as a kind of evidence, such that if I simply were able to develop a complete account of the empirically relevant data, it would reveal a pattern that would tell me which response from my friend is more likely, and thus will give me a method for discerning the most reasonable course of action. (i.e., if the probability is higher that the friendship will be restored, then it is more reasonable to pursue reconciliation.)
I don't think this is actually possible, given the complexity of human interactions--there are simply too many factors to consider. Of course, that doesn't change the fact that sometimes we have to make a decision with the information we have, and often this involves treating some actions as more reasonable than others. But I suspect that such decisions have less to do with genuine reasonableness, and more to do with pragmatic responses which we then convince ourselves to be reasonable.
But, even if we suppose that we do have enough evidence to determine that one decision is more reasonable than another, this doesn't mean there is no good reason for the other decision. In fact, to use the example above, it may be very reasonable to conclude: "I know there is a very high likelihood that this friendship will not be restored, but it is a virtuous thing to attempt, and to hope for, and so I will try, even if it doesn't work."
All of this is meant to provide a bit of context for my initial statement. When it comes to the available evidence, it may be that some feel that they have a great deal of empirical and rational support for the belief that there is no God. Yet, they may recognize that there is something nevertheless very compelling about seeking God, and that it is certainly not unreasonable to hope in Christ in spite of the possibility that their belief might be mistaken.
At the same time, however, it is not unreasonable for the non-theist to conclude that it is likely there is no God. A sincere Christian does not need to feel ashamed or tainted by admitting this, nor should they condemn anyone who feels compelled to draw such a conclusion.
It is here that the verse quoted in my blog post heading (Psalm 14.1) has particular relevance, I think. Often it is interpreted as a way to point out the stupidity or evil of atheistic worldviews. And, there are probably atheists to whom the verse does in fact apply. But, the majority of atheists I know would not fall into that category. Why?
Well, the key point, it seems to me, is the 'in his heart': what the verse seems to indicate (and a brief examination of commentaries seems to bear this out) is that the fool is someone who, because of their desire to be evil, wishes deep down that there isn't a God. That is, the fool wills that there not be a God, in the hope that such a willing matches up with reality.
And, quite simply, most atheists I know are not like this. It's not that they really, really hope there isn't a God, because they love their lives of sin. It's that they have searched, and struggled, and considered the possibilities, and can't see how it makes sense that God exists. And such skepticism and doubt are not, in themselves, unreasonable. I assert that once believers in God are able to admit this, it frees them up to be both more humble in their interactions with unbelievers and more honest with themselves (and others) about their own faith.
And, there is one final point I'd like to make about the fool: if it is true that the fool is one who secretly wishes that God does not exist, then it seems quite reasonable to conclude that we are all fools from time to time, for what is willful sin, if not the desire, in that moment, that God would not exist? And, it seems reasonable to say that we all sin willfully--I agree with Chesterton's statement (paraphrased) that sin is the only Christian doctrine that's fairly easy to prove, just by looking at the way people live.
So, let's keep this in mind the next time we are tempted to call someone a fool for not believing in God. Chances are, we've all been in that state of mind more than we care to admit. And recognizing that belief in God is no simple task just might make it easier for us to foster the kinds of discussions that encourage unbelievers to consider belief as a viable option.