Simple Servant of Jesus
from my knowledge, "pagan" is an umbrella word used by the monotheistic religions to denote idol worship or polytheistic worship. of course, a little research goes a long way. : P
Pagan is a word that basically fits every religion outside of the 3 major abrahamic religions, Judaism, Christianity, and Islam. Baha'i is TECHNICALLY abrahamic, but it involves cultural/religious influence from hinduism, so I would consider it also pagan.
Basically, that which is pagan cannot be Christian because the two words are contradictory. Don't call a Muslim or a Jew a pagan though, because it's incorrect. All three religions are Abrahamic in origin, and worship the same god (technically... though Islam represents God under a different light). For this reason, they are not pagan.