This is the third post in a series on faith and doubt.
Christians don’t ponder the relationship between faith and doubt out of idle curiosity.  We believe that faith is crucial to our salvation.  Many of us have been taught that doubt is the enemy of faith and leads to our condemnation.
Some kinds of doubt reside at the very heart of faith.  
Finite minds wrestling with infinite mysteries must live with a measure of intellectual uncertainty.  For instance, God is Triune.  Providing a final, precise conceptual expression of the Trinity remains beyond our mental reach.
Faith also involves trusting that God will be by our side and on our side no matter what may come.  Acting on this trust today is inherently risky, because we cannot know what tomorrow brings with any certainty.  Faith means taking God at his word, and that can sometimes leave a lump in our throat. 
There is nothing damning about these kinds of doubts.  
However, there appears to be a kind of doubt that places us outside the embrace of God’s redemptive grace.

The writer of Hebrews reminds us that many of those former slaves who escaped Egyptian oppression, passed through the Red Sea, and wandered into the desert for forty years never entered into the Promised Land.  He writes, “So we see that they could not enter in because of unbelief.”  (Hebrews 3:19)
Some kind of doubt—some sort of “unbelief”—barred them from the land of milk and honey.
I will call this Fool’s Doubt, largely because of this passage from the Psalmist: “The fool says in his heart, ‘There is no God.’”  (Psalm 14:1)  
As I will discuss in the following paragraphs, Fool’s Doubt is, paradoxically, a kind of hard-hearted certainty essential to idolatry.  It is the insistence that something else be allowed to play the role of God.  
But I’m getting ahead of myself.  We’ll come back to the connection between Fool’s Doubt and idolatry eventually.  First, we should look more closely at the pattern of the fool’s doubting.
Foolishness and ignorance are not synonymous.  Especially in our age, there tends to be a high correlation between sophistication and foolishness.  And so it has been over the centuries.  The writer of Proverbs says, “The way of a fool seems right to him, but a wise man listens to advice.”  (Proverbs 12:15) 
Fools lack humility about what they know.  Ironically, they are often quick to call into question what others believe because of their utter devotion to what they belief to be true.  Selective skepticism is a favored intellectual posture in the 21st Century.  It takes various forms, so I’ll give only a few examples.
Some fools say that all beliefs are a result of social and cultural influences such as parents, teachers, authority figures and peers.  It follows that such beliefs cannot possibly be true.  Generally this is said with a smug certainty and an air of intellectual superiority.
Here’s the problem.  What the fool has said about my religious beliefs applies equally to his or her own beliefs about the origin of ideas.  
That is to say, their own belief that social and cultural forces have shaped my beliefs must also mean that cultural and social forces have shaped what they believe as well.  So why should I believe their concepts any more than the ones I already take to be true?
Following the same pattern, Darwinists of late have been pressing hard the idea that evolutionary forces give rise to belief.  So, they argue, those religious beliefs have no validity.  
But if evolutionary forces have given rise to my religious beliefs, surely the same goes for all human beliefs.  Including the Darwinist belief about the evolutionary origin of beliefs.  The Darwinist theory of how we arrive at beliefs undermines their own position in precisely the same way that they say it undermines religious belief.
No one is a fool for believing that social or evolutionary forces shape human belief.  In fact, their sophistication suggests that they are too bright to believe that the kinds arguments outlined above are genuinely sound.
Foolishness lies elsewhere.  It lies in the kind of trust that they place in their own knowledge.  It is the trust placed in a false idol.  
This brings us to the connection between Fool’s Doubt and idolatry, and that is the topic for the next post.