I did not fully comprehend the mythological and sociocultural evolution of "good" and "evil" as concepts, until reading Nietszche's "Beyond Good and Evil", which is an absolute masterpiece and essential reading for anyone leaving religion behind them.
IMHO, the root problem at the heart of all religious belief, is the futile attempt to quantify religiously contructed definitions of "good" and "evil". In simple biological terms, that which is good, promotes survival, that which is bad, threatens survival.....all the other convoluted layers society and religion has attempted to add to this basic premise leads to nothing but hypocrisy and circular contradictions.