And there is no need in the US to rely on a higher mystical authority to decide if something is right/just/fair, our society that creates its rules define such concepts. And our society has decided that such penalties are right/just/fair. In the US these decisions are made, ultimately not by corrupt politicians, nor the corporations that line the politicians pockets, but a jury of one's peers. We have jury trials for a reason, jury's have an obligation to not only determine guilt, but also evaluate the 'fairness' of a law.
While i agree that trials by jury do give the possibility of a greater degree of fairness i would say that taking the position of letting the state decide your own definition of whats right/just/fair to be dangerous. It is true that for the most part a lot of laws are in line with what most people feel to be right but to say you don't need to think about it because someone else is for you is nothing short of insane. It is the responsibly of each individual to to decide these things. Government don't always get things right. It brings to mind war crimes and the defense that you were only doing what you were told. Having said that that excuse does probably wash sadly in most of the western world.
You right people don't need to rely on anything mystical just there own brain.