It's to reinforce their own delusion in a world that is increasingly skeptical of Christianity. The film could be considered propaganda, but I disagree with the politics and values of the vast majority of entertainment I like. My favourite song is Supper's Ready
, a song about the Book of Revelation's apocalypse, by a band with a name from the Bible. The song ends with an incredibly pro-Jesus sentiment.
This stuff doesn't really phase me any more. The belief system is just so ingrained in our society, and basic Christian philosophy is so important to the development of my country and why I'm so fond of it.