I've seen this sort of thing before, that "God" must know what it feels like to be immoral or evil else it can't be a god. I can't say I found it compelling even from an atheist's perspective; it's certainly far from being a magic bullet to shut up an Christians.
At the age of five, Skagra decided emphatically that God did not exist. This revelation tends to make most people in the universe who have it react in one of two ways - with relief or with despair. Only Skagra responded to it by thinking, 'Wait a second. That means there's a situation vacant.'