Tonight it was "Is God a Man or a Woman?"
I stumbled around with "we really don't know...usually we refer to God as him...but since God isn't human maybe he's neither a Man or a Woman...or maybe he's both"

That of course didn't suffice, so DD4 changed the question to "Is God a boy's name or a girl's name?" grin

My children constantly remind me of how little I know. I keep fighting the urge to pretend there are pat answers to these kinds of questions.