Musing on morality

I was just pondering a question of morality and thought I'd write it down to see if it makes sense. It stems from an argument I have with my dad on whether morality can change with circumstance or whether it has a finite set of standards that dont change. I believe that there is a core moral standard and that we as a society are always moving towards it. I was thinking that if a person accpets a religion they are in essence accepting a set of moral standards set by an omnopotent being. However as far as I can determin these religious guide lines can become out dated (such as christian views on gay marriage) and this serves as evidence that A: the religion is not governed by omnipotence and B: that the previous moral standard was wrong. The very nature of the religion implies that we are looking for moral guidance and direction and so I would suggest that things like drug abuse, dictators, petty crime, war are humanities ebbs and flows on a meandering river that will eventually lead to an ocean of, umm, neutrality?