I think my years of writing fantasy have contributed to my skeptical view of the world, in particular spiritual concepts.
On the face of it, this might seem like a contradiction in terms, but it starts with how I approach new information. History facts and geographical nuances can spawn new stories (or how about the typo "left at the alter," which I added to my mental file recently) ... but so can mythology, religion, pseudoscience and modern "fringe" beliefs such as past lives. When I read about these things, my first reaction is not, "I believe that: it could be true," it's, "This would make a great story ..."
When I look at such concepts, what I often see first is not potential enlightenment or a way of understanding how the universe works. Instead, I see drama, cost, consequence, plot barrier and tension.
And I've taught myself to structure beliefs, higher powers, etc into a plausible world system. When you approach concepts with the mindset that anything is equally possible, the corrolary is that no single possibility stands out as truth. I am openminded: anything could be possible. But I am also unconvinced: (almost) everything just sounds like a good story to me, not an expression of reality.