Missing the entire point of relativism in my opinion. Of course god can't be real and unreal at the same time for the theist. For the theist it's real, only real. But relatively for the atheist (which is a whole separate, non-connected, instance of an opinion/believe) god isn't real. These possibilities live inside their own relative worlds for each individual.
But you know... your explanation of relativism is also true. Relatively speaking.
RE: What is Relativism?