ICYMI ... the controversial rapper released a music video for his song "J Christ" -- sending shockwaves through the religious world. In it, LNX plays Noah, captaining his ark through rough waters, and even shows him as Christ on the cross. He also breaks the devil's ankles in a one-on-one basketball game for good measure.

The lyrics only add to the song's religious ties ... featuring lines like "Back up out the gravesite/Bitch I'm back like J Christ" -- so yeah, you could say religion is a main theme.

While certain Christian rappers and groups have expressed disgust with the song and video, the Church of Satan loves it ... magister David Harris tells TMZ he's giving the video a thumbs up, calling the imagery "fantastic."

Harris notes how Lil Nas X raps about his ability to go viral, equating it to his church's belief in "lesser magic" ... basically the ability to manipulate people into doing what you want -- which DH notes is lining Nas' pockets with cash.

The magister (kinda like a cardinal to Church of Satan members) says his church -- which doesn't actually worship Satan and instead touts being your true self, personal achievement and living life to the fullest -- isn't obsessed with iconography like other churches ... you'll never see them react to portrayals of the Devil with anger.

Harris's got receipts to back that claim up ... having previously given a stamp of approval to his "Montero" music vid in spite of the depiction of Satan (he also lauded the moment Lil Nas kills him and takes his crown.)

Magister Harris only had one tiny criticism for Lil Nas X -- "J Christ" wasn't enough for him ... DH says he's so talented he wants the rapper to direct a feature-length film!