What We Must Keep In the Public Realm

It occurred to me recently of the idea of what should the balance be between believing what the truth most likely is: There is a God and that one religion is true or; there isn't a God at all and that we exist from natural processes with no Divine interference.

I think that we must keep doubt about any one religion being true and favor the belief that there most likely isn't a God based on the evidence available, and that we should conduct ourselves to be the most moral society possible due to the non-existence of divine authority and morality.

Wow what a sentence.

We must keep this in the public realm, and not have old superstition and religious ideas that are outdated, to being the main state of mind. That doesn't mean there can't be knowledge of religion or discussion about it, even favorably. It is only to make sure there is no religious domination over government and we can have a free and open media without religious filters in it. (Not to mention any corporate monopoly or domination over it either)

Why is this not a good idea?