As for the community: keep being an ethical person to deal with, behave like a good person. Honest, helpful, loving. People will in fact eventually realise they prefer, given the option, to deal with a decent atheist than a religious asshole.

I'd imagine this will work better for outsiders interacting with the community than for formerly religious members of the community. The still-religious community members might see it as a threat to their identity to accept that one of their own could still be a good person after no longer observing their tenets. There's less cognitive dissonance involved in dealing equitably with outsiders with questionable beliefs.