Radiolab had a show on the thin line that separates certainty and doubt. The first segment dealt with someone named Jeff who began with a solid conviction that there is a god and what happened to him and his god-believing fiancée.
I thought the story was interesting, though a little too neat in how it evolved, and was wondering if the events did not transpire as described. I became skeptical because of the fact that although the events took place in short intervals over several years and the story became interesting only in retrospect when those episodes were stitched together, the narrator had recorded key events as they transpired. But maybe radio producers have a habit of recording all the time just in case something interesting turns up.
But even if some of the elements are embellished or re-constructed later or even fictionalized, the basic outlines of the story are common enough in that it demonstrates the immense pressure that people put on themselves (or have put on them by those around them) to believe in a god.
Here is the episode that lasts 24 minutes.