What is ghost?
Ghost is an ongoing rock band/creative project started in 2010 by Swedish musician Tobias Forge. On stage, Forge plays the charachter Papa Emeritus IV (also known as Cardi or Copia). Though the music that Ghost makes is very real, there is an overarching fictional lore. For example, within canon, Ghost was started in California in 1969 by Nihil Emeritus, when in reality, it was started in 2010 in Sweden.
Am I going to hell for liking ghost?
Probably. Besides being known for their super theatrical performances, Ghost is known for their use of religious imagery. Tobias Forge is outspoken about being a Satanist, and the band reflects this. The theming of the band is an inversion of the Catholic church. Papa Emeritus is dressed in a pope-adjacent robe, and the lyrics of songs often times make mention to worshipping Satan. (Please note, Ghost is really hamming up the "worshipping Satan" thing, since that's what a lot of people think Satanism is. On behalf of Satanists, we don't actually do that.) The theming reflects the aim of Ghost, which is to call out the issues with the Catholic church, and to have fun while doing it.