I'm reminded of the discussions I used to have that reasoned on the Catholic concept of confession and forgiveness. The conclusion I/we used to come to was that Catholics could pretty much do what they liked, and as long as they confessed their sins, the gates of heaven would remain open to them.
I would like to think that those with a religious sense of rightness would do right for its own sake and not for fear of eternal punishment.
The evolved animal knows that he can get what he needs by co-operation with others and not by harming them.
What of the much noted statistic that the atheist/agnostic makes up only 2% of prison inmates ? What restraints act on the balance of these ones to keep them law abiding ?