Crowley doesn't want to imagine a God who isn't more forgiving. It's why he's asked for all sorts of guidance, even 6000 years after falling. Even after all of the silence. Even after turning his back on Heaven. He doesn't think She's like that, not really. And, most importantly, Aziraphale doesn't think she's like that.

And the angel needs his faith.

"We've still got the chance that she's better than, well, I think," he says. "More like how you think."