It's kinda funny. I've read that book many times. I'm very much familiar with it. In fact, I used to teach from it.
And never, have I found a satisfactory answer to the question you're avoiding.
How does God define murder?
Why wasn't Joshua's slaying of innocent women and children by cutting their throats, murder?
Was it the fact that God commanded it?
How would we be able to tell today, if someone did something similar?
How do we separate those who really murder because God says so, from those who are just saying that?
Or the ancient world. Did you know that before the advent, and continuous pressure of the Christian faith, that:
a) Infanticide was legal? (Outlawed by edict of Christian Emporer Valentinian I in 374 AD)
b) Abandoning children to die of exposure was legal? (Outlawed in same edict)?
c) Killing of older children (honor killings) was legal? (outlawed in 325 AD)
d) Slaughtering human beings for sport in the gladiatorial arenas was legal? (Outlawed by edict in 376 in the east and 404 AD in the west)
e) Nuclear marriage was a joke? (a man could cheat on his wife with anyone, male or female, without punishment).
f) Pedophilia was an accepted fact of life?
And on and on and on. The most infuriating thing about you people is that you state that you don't need God for your ethical system, and then you go on to state that your ethical system comprises exactly the things that were completely alien to the world before the advent of the Christian faith, things for which thousands of true-believing martyrs went to their deaths.
Before Christ and his church, human life was cheap, might makes right prevailed, charity was not something you did for goodness' sake, but to get ahead etc.
In other words, you're cultural Christians and you don't even know it. Most of you would blanch at the idea of drowning an infant with Down's syndrome, but that happens in the non-Christian world all the time.
The next time you guys decide to trash the Faith, remember--most of your belief system as to what is right and what is wrong was formed by it.
So how do we tell when one is commiting murder under the libertarian dogma? How do we separate those who are really responding to an initiation of force, from those who are just saying that?