I'm trying to build a world loosely based on ideas about afterlife in Christianity. In my world God is nowhere to be found and supernatural forces are split into three factions: Hell, Heaven & Purgatory. Each faction has a ruler, and army of angels and human spirits.
Michael rules heaven with army of angels and saints (spirits of good people)
Lucifer rules hell with his army of devils (fallen angels) and demons (spirits of evil people).
Gabriel rules purgatory where angels loyal to him fallowed him after disappearance of god. Gabriel believes that humans are flawed, but their uniqueness is in the journey for improvement.
All three factions covertly compete for human souls. Good people go to heaven, bad people go to hell and those who are flawed but have a chance in redemption go to purgatory.
How to call the angels and human spirits in the service of the Purgatory?
Preferably I would like something that references Christianity, Judaism is OK too.
1st Edit
I don't need biblically correct, just names at least loosely connected with Christianity, that make sense in my world. I don't want to introduce supernatural beings from other religions, like Shintoism or Hinduism or whatever.
I added purgatory because good & evil duality is very boring and has been done to death. Three way fights are much more interesting, whenever one side starts winning the other two gang up together against it, until the new leader emerges when alliances shift again. The unstable dynamics gives me more interesting background to work with.
Conclusion
After some thoughts I decided to combine suggestions from Werrf & Pedro Gabriel.
I decided to keep the name of the third realm as Purgatory, but will use ideas from Sheol. My reasoning is that the term Purgatory is known while the Sheol isn't.
I'll call the angels that rule the third realm watchers since that name fits with my story and there's apocryphal references in Books of Enoch. The alternative shepherds was also good but reminds me too much of Jesus. And those angels are far from good shepherds.
I'll call the human spirits that serve the watchers Rephaim since it has a somewhat sinister sound. The translation shades fits great into my story.
In the end I know that is far from biblically correct, but I don't strive for correctness. So I decided to use elements that I believe serve my storytelling best and at least to my ears sounds good.
In short my idea is described below:
God is absent and without it "angels" play a wicked game of who collects the most human souls by peddling their influence to humans using souls they already have as pawns.
After the soul is sent into one of this"realms", the "angels" might consider it useful enough to return it to Earth in order to bring more souls. They offer the soul a deal, go back to Earth to do their bidding as saint, demon or rephaim, in return you will receive respite from torture, chance to save loved ones or harm your enemies. While the soul is on the Earth, it's job is to influence humans toward the path that leads toward their own realm. Spirits in general work on edge cases, if someone is a remorseless killer, saints & rephaim wouldn't bother with someone who is destined to hell. However as soon as the human soul could go either way, they try to influence it.