Earlier quoted context omitted.
That's not an atheist. That's an agnostic theist (aka deist). Gnostic Theist: My God exists. Agnostic Theist: I accept the concept of deity(ies), but it's not relevant to me Agnostic Atheist: I don't accept the concept of deity(ies), but it's not relevant to me. Gnostic Atheist: Deities do not exist.
Atheism does not mean that you believe deities do not exist. It means you do not have the belief that they do. The absence of a belief in something does not imply a belief in the absence it. A definitive belief that deities do not exist is sometimes called strong atheism.
Atheism is lack of beliefe in deity due to lack of evidence of any such/any deity.
This pushes the burden of proof onto believers.