None. I'm an Atheist.
I am a practicing Roman Catholic. AKA I am a Roman Catholic that goes to church every week.
Catholic, myself. :)
Also, to reduce confusion:
Theists believe there IS a god (or gods).
Atheists believe there is NO god.
Agnostics don't know one way or another. (The word means "I don't know"!)
catholic but I don't go to church