Primitive people thought epilepsy was demonic possession, and once medical science developed they saw it for what it was. And it wasnt demonic posession. Before germs were discovered, people thought they were being punished by evil spirits. And so on.
My point is, every gap in knowledge was filled by 'god', karma, spirit, or some mystical entity. But as we gain knowledge, these entities disappear.
So my question is: If you're religous, do you ever feel that sooner or later your present beliefs will also be eclipsed by more knowledge as we advance? Does it scare you?