"Within good reason" and theism don't go hand-in-hand. You can't think anything with good reason when you think the universe is only 6,000 years old.

Not all who follow the Christ (and I gather you are speaking of Christians given your 6,000 year supposition) think that and I know this from personal relationships with a few genuine Christians. One thing that liberalism and even conservatism, albeit to a lesser extent in my own personal experience, do is force people to focus on their supposed "differences" instead of the things we all have in common. Black, white, have, have not, etc.
If we were truly as different as some would have us think, then how is it we can (as did my parents) have children together? It is understandable that morals are often based in religious beliefs, but if those morals are true and good then how does it lesson that goodness, that truth and their relevance any if some think them given by a deity?
It does not. No one needs a God to tell them what is right or wrong, but if we were in no need of any moral guidance and enforcement of same, then why do we have laws and the police and military to enforce and protect us from ourselves?
Because we are at once both human and inhumane. Ah well, thank you for listening to the rantings of an old man. Be well.