Jonesthe Spy wrote:A Theist (for lack of a better term) believes that existence includes a spiritual aspect of some sort that transcends the material universe as we normally interact with it.
An Atheist believes the universe has no spiritual dimension of any sort and that the material universe we perceive with our senses and devices is all there is.
An Agnostic believes there is not enough evidence to conclusively judge the previous two beliefs.
Theism is almost always used to refer specifically to people who believe in a God or gods. I don't think that someone who, say, were to believe in ghosts, but not in any gods, would be properly called a theist, or even a deist. They'd be an atheist who believes in ghosts. (A)theism are terms that refer to the specific claim about the existence of a God or gods. As it happens, most people who are atheist also do not believe in other supernatural manifestations, but this is not necessary.
I think what you are calling an atheism would probably be better described as empiricism; what you are calling theism would probably be better described as mysticism. Or perhaps naturalism versus supernaturalism.