That's a good question.* They might not be atheist.* There's a lot of reasons why someone might be non-religious. They might be busy with work and school and don't think about religious things at all. They call themselves "spiritual but not religious" but to me, that's still religious.* They just like a different word better. They might be agnostic, meaning "They don't know". Or maybe they are atheist and choose to say "I don't believe in God".* They might even think that "religion is wrong" and fight it. So the answer is "sometimes but not always".