My dad, albeit accidentally, provided the seed of my doubt. He taught me to be skeptical and only believe things with verifiable evidence as he himself is a scientist. I'm not sure he ever expected me to apply that to his religion.
Even if the open windows of science at first make us shiver after the cozy indoor warmth of traditional humanizing myths, in the end the fresh air brings vigor, and the great spaces have a splendor of their own - Bertrand Russell