For some reason this seems really hard for people to accept: That religious people actually think there are consequences for their choices, even if no human being ever knows.
The thing about religious people is, even if they lose their religion, they don't suddenly start committing all the wanton acts that when they were religious they insisted they only didn't do because fear of God was holding them back.
Swearing an oath is similar. You're not more or less trustworthy simply for being religious; it's just that, it you're religious, you think you are (but actually it's just based on internal factors of who you actually are and how you behave).
I’m an atheist, and I believe that there are consequences to my choices, even if no human ever knows. Maybe I don’t understand what you are trying to say.