Actually I think you have it backwards if we're to speak in scientific terms.
Apologies, but I consider the miscommunication of scientific terms (despite almost universal good intentions) a serious problem. Thus I would ask of this:
Theism can not be considered a theory because it fails to meet the standards to be recognized as such.
what are the "standards" we scientists use to determine whether something can be a theory? In particular, how do such standards differ from a claim that something is:
At best it's a hypotheis.
?
Atheism is the opposite. We take all the available evidence in the hypothesis of theism which leads to the conclusion there's no evidence for the existence of gods
What are your arguments against the argument from cosmology, particle physics, and theoretical physics for a theistic cosmology as presented in e.g.,
Amoroso, R., & Rauscher, E. (2009).
The Holographic Anthropic Multiverse: Formalizing the Complex Geometry of Reality (
Series on Knots and Everything vol. 43). World Scientific.
?
Why do other promoters of the anthropic principle favor it in part because they believe it to remove the need to answer questions concerning a theistic cosmology?
...thus the claims made by the faithful are simply that..."claims"...
"And thus the native hue of resolution is sicklied ov'r with the pale cast of thought..."
Seriously, the best way to separate the sciences from religion is to refrain from formulating either atheism or religion in terms of scientific theories or frameworks or hypotheses or anything else. It is problematic enough, thanks to modern particle physics, QFT, and the new status granted to cosmology, to separate metaphysics from physics. Add an equating of atheism with hypotheses or theories (and more so theism) and you do but further blur the line between pseudoscientific nonsense, metaphysics & philosophy, and the sciences.