Believers have long argued for the existence of beings in the “spiritual realm” which affect the physical universe but cannot be physically detected (except in very certain circumstances and with very few exceptions).  This is convenient, of course, because the believer is free to posit whatever entity he or she wishes without having the arduous task of defending that assertion with actual evidence.  What does “spiritual” mean though?  The dictionary defines it as follows:

1. of, pertaining to, or consisting of spirit; incorporeal.
2.  of or pertaining to the spirit or soul, as distinguished from the physical nature.

That doesn’t really tell me much.  If we’re talking about incorporeal things apart from the physical nature, how is this any different from being imaginary or fictional?  Why do we make such a concessionary definition for a word like “spiritual” when the end result is really the same?