Believer says: Atheists have no higher power to justify morality.
But skeptic says: Well, the way I see it, wherever there are two people together, morality is there, too. Say in one extreme, people bully one another in their group; that’s their morality. In the other extreme, people are generous toward one another; and that’s their morality. In other words, it’s never possible to have no kind of morality in a group.
As for a higher power or standard to justify morality, standards of morality are relative--they change, they vary from culture to culture as well as from religion to religion. I say there’s no such thing as a higher standard of morality, but there's only a different standard.
Recap: Morality is intrinsic in a group. It’s unavoidable whether for better or worse. And a belief in God isn't automatically a higher standard for morality. It's really just a subjective thing.