Usually Christian films (even awful ones!) are marketed to church groups and that helps sales, but I am unaware of that happening with this movie. Perhaps Evangelicals were put off by the Catholicism in this movie. The R rating and scenes of torture were probably also a factor. If it wins any Academy Awards that should help sales. As for me, I will have to wait until it comes out on DVD before I get to see it.
Hacksaw Ridge is supposed to be another really good Christian movie.
Good idea about a revival of Christian art. The American Bible Society in Manhattan used to have a museum of biblical art, but that division has closed down.