There’s a large and complex tradition of Christians disliking the church, and of sometimes referring to “Christianity” negatively. One of the many dumb features of our dumb modern culture is the assumption that the denominations that were created/influenced by the Moody Bible College and its offshoots in the 1870-1900 era are somehow “more core Christian” than the outfits that have been around for many centuries.
For a sampling of Christian anti-Christianity as high-ish art, see http://www.poetry-archive.com/e/the_hippopotamus.html.
