Yes, the bottom line is that if life carries with it eternal import, then there has to be a universal standard that defines good and bad. It can't be a floating scale based on the mood of the day, the whim of a particular individual, or the period of time in which one lives. If God is responsible for all creation, then he owns the definition.
If you don't believe in God and instead believe that everything came to be out of nothing (which takes far greater faith, when you consider the complexities all around us), then there is no absolute right or wrong. And therefore, you really shouldn't (and don't have a right to) advocate for anything.
If you don't believe in God and instead believe that everything came to be out of nothing (which takes far greater faith, when you consider the complexities all around us), then there is no absolute right or wrong. And therefore, you really shouldn't (and don't have a right to) advocate for anything.