Sure they can rationalise this all and they do so with or without a god. Plenty of 'god fearing' folk rape and murder. Their belief in the authority of a god does nothing to stop them. It is not about authority and proclamation, it is about what is good in a rational and constructive way. You, being a Christian, are obsessed with authority, yet that alleged authority doesn't stop many Christians and religious people from committing crimes.
Deicide,
You still haven't given an acceptable answer to the question "who sets the standard for morality and good?"
The standard is the golden rule (which we know was not original to your Jesus). Christians are obsessed with authority but you don't need a cosmic tyrant to tell you what is right and wrong. It is rational and logical to not want have pain inflicted on you and hence it follows that it not be inflicted on others by you either. Pretty simple.
MCWAY just showed you that your are incorrect. Just because someone does not want others doing him/her harm, it does
not follow that he/she won't want to and won't do harm to others.
A huge part of the reason we are in this bad global economy is because economists and investors were sure that when it comes to financial decisions, "most people will do the
right thing most of the time." But guess what, we all eventually found out the hard way that "most people will do the
wrong thing most of the time." And it's not because of ignorance, but because of greed, irresponsibility, negligence and selfishness.