Atheist, Antitheist, and Antireligionist
 
I am an atheist (lack belief in or rejection of god$).
 
I am an anti-theist (rejection of or see theism as harmful, ie. belief in god$ or the concepts themselves as harmful).
 
I am an anti-religionist (rejection of or see religion as harmful, ie. all religion or religious philosophy is harmful including ones without gods).
 
This is not full definitions just quick examples.