The social reward system we have today selects for them instead of selecting them out.
There is one bedrock problem under all the others: how to fix this.
Hannah Arendt (in "What is Authority?") zeroes in on the term "religio" in particular, as the root of "religion" with the literal meaning of "to bind [oneself]". If one is bound to a higher law, secular or theological, as common knowledge, then to act against the law is to subject oneself to punishment.
Unfortunately, as we know all too well in software, this state of having a group bound to a law that transcends them is a precarious state indeed, requiring continuous maintenance or else it's liable to be taken over by those who manipulate the rules to preach without practicing. A failure of the rules leads to the "primal father" situation described by Freud in _Totem and Taboo_, where those who feel dominated band together to kill the person who bound them, and then produce taboos to prevent the situation from occurring again.