There's a lot (and I should say, being portentous, a vast hinterland) of people who just keep on keeping on and don't measure their morals between authoritarian poles. They don't have, nor want, an external force to guide them in their ethics. And in fact feel slightly demeaned when they have to call on precepts of goodness they have not themselves evolved.
That's you and me, basically good, but not because of magic-man-in-the-sky's edicts.
So how does that work, and how do you defend that?
Easy. I made my own moral compass, and its direction is rounded by my contemplation. I am not so stupid that I need orders to be moral.