‘If there was no God what would make that true?’
I stated ‘don’t do to others what you don’t want them to do to you’; this is the very basis for natural enemies to form alliances that enable cultures and civilizations to thrive...it is a very basic and human self preservation ethic; why is it necessary to postulate a deity to provide instruction into what is,after all, basic instinct...?
I don't believe that at all. History shows that alliances, especially between natural enemies, are formed out of self interest, not altruism, and last only as long as they are useful for that end.
"why is it necessary to postulate a deity to provide instruction into what is,after all, basic instinct...?"
I don't believe the golden rule is a "basic instinct", again history shows just the opposite. And even if it were true all you are positing is pragmatism not objective morality. Apart from God, if someone whats to violate the golden rule and they prosper from this behavior that what conceivable basis would you have to say that is objectively "wrong"?