Is there a god, or god claim, involved? If not, then yes, you can still use your atheist membership card. Atheism is merely a specialised subset of scepticism - skepticism if you really must - dedicated to one single subject. That's all it takes.
At the age of five, Skagra decided emphatically that God did not exist. This revelation tends to make most people in the universe who have it react in one of two ways - with relief or with despair. Only Skagra responded to it by thinking, 'Wait a second. That means there's a situation vacant.'
