One's not in a mainstream religion (5)
I believe the answer is:
pagan
(Other definitions for pagan that I've seen before include "Unbeliever" , "Polytheist" , "Not conventionally religious" , "Infidel" , "Unchristian" .)
I believe the answer is:
pagan
(Other definitions for pagan that I've seen before include "Unbeliever" , "Polytheist" , "Not conventionally religious" , "Infidel" , "Unchristian" .)