The standard isn't "can't include God", but "must fit the facts". God is unprovable and untestable; making a theory depend on a God makes the theory unprovable and untestable. Most scientists who also have religious beliefs don't see the two conflicting; their religion gives the why, their profession the how.

Or more succinctly, no one is blackballing scientists for saying "I believe God caused the Big Bang". But claims of, for instance, "I believe the world was created 6000 years ago over a period of 7 literal days" requires some evidence beyond "My understanding of the Bible tells me so", and doesn't jibe with your initial statement of empirical scientific study.

The bible, esp. genesis, is taken metaphorically, or else a lot of problematic interpretations will arise.

Also, even scholars of the Abrahamic faiths do not readily disclose their intimate religious faith, lest their work be discredited — such as a professor who studies Christianity, but holds Islamic faith.

https://www.youtube.com/watch?v=AQhMllQ-ODw&feature=emb_logo