I just went through the "Christian" genre Spotify playlists, and pretty much everything there is pop / contemporary / rock, which is a real shame given the availability of a wide variety of subgenres on the platform. There should be playlists for categories such as:
Sacred Choral Music, e.g. John Rutter, Rachmanninoff's Vespers, some Eric Whitacre Pax Christi
Music dedicated to the Mother of God (Marian Hymns) Mater Mundi
Orthodox / Eastern music, e.g. Russian, Greek, or Coptic
Southern Gospel, e.g. Statler Brothers, Gaither Family
Was searching for some diversity in my Christian music too and this post was very helpful, thank you! will definitely be adding some songs to my alternative Christian playlist and maybe you can find some you enjoy also!