Bant, you need to bear something in mind: max didnt tell us to commit murder, what max tried to elaborate is that we are imprisoned by a form of a so-claimed "spiritual" entity within us that is spirit, which is basically a set of morals and attachments to the correctnesses of the social norms and their root values.
What caused this to happen is so many factor, one of which is the irrational traditional mix that occured between people and their nations centuries ago, which can be classified under many majors but what we can take rationally and specifically is the mongoloid self and the negroid self having a strong dominance over many peoples throughout the world especially the leading people at those times, the well known caucasian peoples, this, as i said, sat a very negative effect on people free will that max quite over exaggerated with their examples, lets look at it simply, what i said in the OP is actually an example max used in his book, defining something that could be of importance, that thing would be the effect if the christian soul on the european bunch after the influence of the church over the roman empire that led to it turning into the well known holy roman empire, so due to the morals pushed by christianity, we could say that it had had a strong influence of the previously defined spirit, causing people over ages later trying to be more "open minded" by rejecting god and adopting atheist values, yet they would feel in disgust if they saw a man having a protected sex with his sister, how selfish of them! This can be due to what you may ask? Exactly, due to the christian values having mixed perfectly with one's spirit and the norms of the society causing it to be an important value of yours! Something "sacred" because its simply alien to you! You didnt consider anything over all, but what about murder for example? Look, max isnt a social philosopher, he is just an ego philosopher that didnt even talk about the effect of his glorious book upon society