On BTW @gaga's lyrics, music videos and performances are really influenced by the Christian religion. Almost every song on the album has biblical references. Jesus (Americano, Black Jesus), prayer (sheiße, judas) she talks about hell in The Edge of Glory. Anyway the whole album is very spiritual. On the other hand most of ARTPOP has Greek mythology references. Aphrodite (Venus), Himeros, Zeus. She rarely talks about a god. Just in dope I think. So I find this very interesting.