Actually, I feel like 'thinking out loud' about that moment. You know it's so sweet, because the lines, "You better listen to her, God did." Are so Brian Kinney. Without knowing what tone he'd use, it could sound the same as his more sarcastic/cynical remarks like, "It fills the void." But the way he says it. It's like an innocent little boy. Just like when he says, "It's for my prince." It's just the way he talks, whether he's being sarcastic or not. In slogans. And it's so neat to see it be so heart felt. He also gave Debbie back a lot of dignity when he said it. Ben was really putting her in her place while they were out in the waiting room. I like when Ben does that, it's right for the moment. But when Brian puts her back "on top", it's very touching.
And since Debbie believes in God, I am sure she was very moved to hear Brian speak as though there is one.