I would use them if they were good, or if I had input on creating them if they were meant to be PC spells. If they were meant to be NPC spells, I wouldn't have an opinion either way unless they were extremely overpowered. I think one or two per spell level is probably enough, anything more may be too much. It's a great way to make the various religions/deities in the game unique from each other.So you play a cleric. What would you think if the DM handed you a sheet with unique spells to your faith?
I agree. Not something I've done as a DM but something I thought should have become RAW a long time ago. Spells being class based just seems antiquated anymore. There are enough spells that letting any class take any spell would make them more unique.When I DM, I allow clerics of certain domains/faiths to have access to spells that the rules as written don't allow them to have. For example, it's ridiculous that tempest domain clerics can't cast shocking grasp. A cleric who worships Lolth should surely be able to cast spider climb (RAW clerics can't cast it). A cleric that worships Auril should surely be able to cast Ray of Frost (RAW clerics can't cast it).
In the same vein, I also remove certain spells from the clerical spell list which make no sense for a cleric of a certain domain to have.When I DM, I allow clerics of certain domains/faiths to have access to spells that the rules as written don't allow them to have. For example, it's ridiculous that tempest domain clerics can't cast Shocking Grasp or Witch Bolt. A cleric who worships Lolth should surely be able to cast Spider Climb (RAW clerics can't cast it). A cleric that worships Auril should surely be able to cast Ray of Frost (RAW clerics can't cast it).
Unless there are going to be clerics of Amaunator popping up all over the place, this seems like it'd basically be a set of spells unique to this character.
In which case, don't just hand them to the player, work with them to create something that will resonate with them and their character.