Similar to a fundie christian, but instead of being a bible thumper who has a belief in God, is an atheist thumper who forces everyone around him/her to believe that God/Jesus/Satan/Heaven/Hell does not exist like he/she does, and that anyone who doesn't agree with his/her strict world view is comparable to a mentally challenged or psycholigically unbalanced person.
Fundie Atheist: Where are you going?
Christian: I'm going to church.
Fundie Atheist: Oh, going to listen to people preach how gays are evil, and that science is witchcraft?
Christian: No, I'm going to listen to people preach on how to be a kinder, more compassionate person, sing some lovely hymns, clap along, and then help with the charity drive for homeless people in third world countries.
Fundie Atheist: Open your eyes! God ain't real! It's all a crock of crap! Fairytales! It's a cult! Church teaches people nothing except how to hate and hurt others different from them!
Christian: Actually some of our congregation members are gay, and our charity drives are for helping people in need.
Fundie Atheist: You're still hurting people!
Christian: *rolls eyes* Look, believe or disbelieve whatever you want ok? But don't force your own world view down my throat ok? If you want to come and see for yourself, you are most welcome. Otherwise don't get on my case, please? Good day.
Fundie Atheist: Cult follower!
Christian: Get a life and a therapist, wacko.