The most important reason anyone is an atheist

[Doubting Thomas]

Rather, the evidential standard required for a given claim is determined by convention or community standards, with regard to the context of the claim in question.

By this definition, the (predominately Christian/theist) community could fulfill the burden of proof by determining that it is met by faith alone and, due to the above statement in the definition of the burden of proof, they would then be meeting it, correct? After all, the community would be developing this evidential standard, so if the community concludes that faith alone meets the evidential standard than they've completed their task, no?

They tried this once. It was called the Dark Ages. That's why we don't let churches run science any more.