I do not understand; how do the faithful know what to believe? Obviously they can't believe everything. So they are skeptical, sometimes. Perhaps that is what the "holy spirit" provides. It guides them to take some things on faith and reject other claims as false. But you need faith in a holy spirit first, so that's bullshit too.
I recall the first little prick that informed me that Santa was a hoax. I refused to give it up until I caught parents playing Santa. That was all it took. So you can't just tell someone not to be faithful. Atheists play the role of that kid who busted Santa....no wonder we are so unpopular.