"Good" and "Evil"

When people use the words "good" and "evil," they do not specify whether according to their morality or common morality because they are usually similar.  (I suspect they are similar because all societies have similar moral requirements in order to function well, but that is a separate discussion).   However, a specification must always be implicit because their can be no objective standard; how can you say what a human life is worth (emotionally, not materially) except by consulting your own unique morals or by consulting the morality of others? I do see how another standard could be identified for the definition of "good," but I do not see how one could argue the standard to be more more right, when their is to way (or standard) to judge the standard itself. 
So, if the world accepts theft as morally correct while a certain individual does not, it is wrong according to the individual and right according to society. Theft may be colloquially referred to as "good" and seen that way by most in this imaginary world... And, in our world we would have no authority to say their world is "wrong" and that our morals are objectively "better."
Furthermore, as Bertrand Russell would say, our concept of "good" cannot come from God, because we ascribed the quality to Him and must therefore have had an idea of the concept to begin with. To define "good" as "God-like" then saying "God is good" would be meaningless. 
Sin therefore, as a transgression before God, must not be considered "evil," especially as the common morality shifts away from its former standards. 

What is a definition of "good" that every society would agree upon regardless of their morals?