Faith is the way forward when we finally accept that we do not know, and never will know "the truth". This is why I say it's as close to the truth as we're ever going to get.
We might just be having a semantics issue here. I think the golden rule is a corner stone for living a life worth living. Unless you're a relativist, I think it's fairly easy to "prove" that valuing the golden rule leads to a "better" life. I guess the question is whether that belief is "faith" or a "value"?