system
Given the following post, respond as if you're commenting on Reddit:
human
[40K] What happens to the souls of the deceased?

I know that those who give themselves/are devoured by Chaos have an eternity as the playthings of daemons ahead of them, but what of those who die with faith in the Emperor?  What is is store for them?  

Also, what happened to those who died believing in the Imperial Truth, or ancient humans who lived long before the emperor revealed himself, or humans living on worlds not part of the Imperium?
gpt
Their souls fade and disperse into the background noise of the immaterium. Then, when something new is born, whatever soul-stuff is in the area seeps back in, reincarnation-style.

Or they fall into the holy cosmic bonfire of the Astronomican and are annihilated.

Or they're eaten by chaos gods.