Nothing stopping them from doing that now. Also, it is a MUCH bigger step from armed robbery up to outright murder. Most petty thieves aren't up to real bloodshed.
Either way, you'd still have a MUCH better chance of protecting yourself in a libertarian society as they actively encourage personal arms, rather than today where we are discouraged and merely "allowed" in some juristictions to "maybe" defend your self.
What forms the basis of libertarian thought is self, and ONLY self, ownership coupled with the Non-initiation of force, fraud, theft philosophy. Anyone acting consistant with that philosophy is a "libertarian" whether they are aware of it or not. It also forms the entire basis for a self-governing social structure that is self re-enforcing and driven by basic human nature. It is also simple enough that even those folks of modest intelligence can be taught the basics and live quite easliy by it. I'm currently teaching it to my two year old and even she "gets it".
Also, nothing in libertarianism precludes you holding your own personal religious beliefs. In fact, it leave you free to only interact with those of similar beliefs. If you want to discriminate, go ahead. Someone else will be sure to take that share of the market you don't want if there is a profit in it.
It all goes hand in hand.
I think you are missing my point.What is the reason that most petty thieves aren`t up to bloodshed?
How much of it is due to the severity of the punishment that goes along with it.
I am postulating that within the system that you are presenting,which is no government or "official" laws that go with it,that deterrent would possibly be removed.
There already exists areas where there is limited enforcement or respect of laws or the teaching to do so.It is in the inner city and in third world countries.
The absence of government and laws for some reason does not lead to a self restraining individual government or to the communal sharing that Marx envisioned.