Story idea: Beings from all over the universe farm billions of planets. Earth is one of the farms. The beings harvest human souls for the light power particles they contain. The light power particles provide all the power they need to exist. All souls are the same when they are ready for harvest. The soul of an atheist is the same as the soul of a devout Christian, Muslim, Jew. The beings know the souls have nothing to do with spirituality and such. The beings don't have gods, devils, or religions. They don't have war, either. They've never even heard of such things.
All humans have souls. The soul is the first product of conception. The human then grows around it. This is true with every single human.
The being's ancient ancestors inserted a trigger into the DNA of humans which acts to cause humans to release their souls into space when they are at maximum light power particle maturity. The only way they can do this is to die. The trigger mechanism also causes humans to kill humans whose souls are ready for harvest. Hence, war, and other means of death.
Souls only become ripe for harvest after their carriers are exposed to certain natural elements such as rays from sun spots mixed with naturally fortified water vapors in the atmosphere, and just the right amount of various dust-borne particles. It is common for this criteria to ocurr in pockets of populations of the world, where at which time the humans in these areas are then triggered to go to war, which makes harvesting quantiies of souls in a short period of time possible.
reaction
the soul harvesters seem like demons