Furthermore, a society that decides its own morals will eventually collapse do to the corruption of human nature.
For example:
Take two people groups. Christians and Atheists.
Christians go based on the Bible's morals and standards on how to live your life by letting the Bible dictate what is right and what is wrong.
Atheists go based on whatever they want. "Choose your own morals" as they would say.
It is not healthy for a person to dictate what is right and what wrong by his prospective.
If I think killing is ok by what atheists believe that's ok because I have chosen my own morals.
Of course that would be wrong... if you had a book to tell you so, but keep on deciding your own morals and see the destructive path it leads you down.
My personal opinion is that it's quite barbaric to do what you "feel" is right and ok.
I have chosen a guide for my life.