It was OK until the end, though it takes a few liberties in the interests of telling a simple, short story.
Evangelical churches aren't increasing in terms of number of adherents in the US, with the expection maybe of Pentecostalism (which has never attracted masses of people anyways to Christianity in the developed world, nor is it likely to do so in the future). This has been the case for at least a half decade or so. And mainline churches have always been more than just liberal modernists, and it's crass and stupid to say people in mainline churches don't really believe in Christianity. I know from my own personal experience that really is a gross overgeneralization.