Humanity begins as this thought, a new human born from the broken, the beaten and the damned. They are the Vessels of the Dead, it's almost the same as a process called reincarnation but with the knowledge of the last life the human Vessels lived to be erased from existence, even though there is an erasure of historical remembrance and existing memories some memories still become a Will and turn the broken Vessel into an Inheritor, an Inheritor Inherits the past skill and strength if they so wishes, the new born and created Broken vessels have a choice, two choices they can choose wether or not they can Live as a New Vessel erased memories and beginning a new life, or Live as a New Vessel and Keep the Will of the Last Vessel they were as. Some choose to do so and some don't, some force them selves to a Will and become a broken Vessel permanently and in result overgo the process of Natural Selection again and be born as a new vessel with no significance to the world.
The human god created exactly 7 Billion Broken Vessels, 300 Million of which was turned into a part of humanity for a span of 600 years after the beginning of earth. But before he could fully revive all of the broken vessels he didn't have time to finish all of them, but with his own wishes he was given the rule to create the Central Fiction, The Central Fiction is this Sphere where the processes Natural Selection and Revival happen. The Central Fiction holds an infinite ammount of Information Surges and is unable to be touched by the physical outside of the sphere. The Sphere is also where the process of Hope happens.
Hope is when a wish for a new vessel is answered, when answering a new vessel or a broken Vessel they are submitted to a wish called hope, this hope is the collective sense of humanity to advance and not go extinct until the end of time, or if the end of time happens they will find a way to survive the ordeal of an ending world.
Natural Selection is a process of resetting a broken Vessel into a new hope, this new hope is turned into a new vessel and end up becoming a new broken Vessel with no significance to the world of Earth, they are just a minor defect and a reset to the last part of humanity they became as.
Hope is the collective will of humanity to survive, and the counterpart of hope is extinction, extinction is the will of a force called penumbra a will of darkness that consumes the vessels and breaks their creation composition of which Barbatos personally created. The Penumbra is an endless void of death and decay, these effects to the vessels if inflicted upon them breaks them and kills them for good, some broken vessels turn into Stasis and become a vessel of which the Penumbra has control over their humanity, well atleast that is how it is written in the books.