I have seen the bottomless pit. It is a volcano. "And he opened the bottomless pit, and smoke arose out of the pit like the smoke of a great furnace. So the sun and the air were darkened because of the smoke of the pit." (Rev 9:2)
So in your world when Hell opens up, all those damned souls are going to be deposited into those volcanoes for eternity.
Hey, did you know this? L. Ron insane Hubbard stole the groundwork for his cult of Scientology from someone else while he was stationed in Germany. He was Navy.
To this day it is beyond belief that people follow a cult invented by a mediocre Sci-Fi writer. In any case, after morons with money spend a veritable hundreds of thousands of dollars to take all the courses Scientology sells them, when they come to the end they find out why this world is so screwed up.
An evil alien named Xenu! Countless other evil aliens were cast into the prisons of dormant volcanoes so they would be locked in there forever. Then the volcanoes erupted and all those evil souls filled the atmosphere. And now they possess people and make them do evil things.
Scientology's courses lead people to find how to exorcise those evil aliens and live better lives.