Opening song says it all
"Give me that old time religion...". This song encapsulates this movie completely because it infers that to believe in God and the rest of it, one need not question anything...just believe...as though to irrationally believe were it's own raison d'etre.
Not only does one believe because one believes, ad infinitum, but one is proud of this nonsensical approach. The film makes this point brilliantly.