Apocrypha
Apocrypha: n. biblical or related writings not forming part of the accepted canon of Scripture. Often considered illegitimate and heretical.
The divine are not what you have been led to believe. There is no one, true religion, and no religion is wholly true. Instead they are carefully curated manifestos of omissions, twisted stories, and half-truths crafted by the deities and delivered to the mortal realm to ensure their obedience.
“God” is not a sentient deity but a hands-off entity, more often a force or energy than a being that can observe and respond - though some angels believe otherwise. Angels are the keepers of God rather than creations and manage its use, funneling it to grant rewards and blessing or dish out punishments and hard lessons as they see fit, as well as sustaining themselves off it. Demons are simply a faction of angels . Each part of the world is governed and occupied by different groups of angels and demons - the angels and demons that ruled ancient Greece are different than those that did the Norse or the Maya - each with their own set of morals and skills. Many factions do not get along and wage divine war on each other, urging their followers to do the same. As religions rise and fall, spread and isolate, the deities must adapt; for example, the angels known as Anpu, Djehuty, and Maat to the Ancient Egyptians now answer to the names Izra’il, Munkar, and Nakir to modern, Muslim Egyptians. If angels do not adopt the new names and customs, or if their religion is wiped out completely (such as Mithraism or the Minoan religion), they can no longer harvest energy from their worshippers to return to God, closing their path to it and leaving them to wither away and die. If the religion is revived, even centuries or millennia later, the angels will be revived along with it. Demons, on the other hand, do not rely on God for sustenance, and will continue existing - albeit with severely wounded pride - long after humans have stopped believing in them. If humans begin to believe in a deity that cannot be portrayed by any existing angels in the vicinity, the angels will create a new one with energy from God.
“God”, “angels”, “demons”, “Heaven”, “Hell”, etc. are by no means the official name for any of these beings. Each region - both mortal and divine - has their own terminology. These are merely the most common terms used by English speakers. In general usage in the West, they refer specifically to those from the Abrahamic religions (Christianity, Judaism, and Islam).
Angels and demons each have complicated social dynamics depending on their region of the world and what religions are active there at any given time. In some factions, angels and demons are synonyms and used interchangeably. In others, what humans call demons are in fact angels that have been tasked with scaring the humans into compliance, or even an entirely different race of supernatural beings altogether. Still others only recognize one or the other, with no mention of the opposite anywhere in religious or cultural texts. In the Abrahamic religions, demons are angels that defied the will of God and revolted against Him, until they were banished to Hell, where they became hideous, monstrous beings hellbent on tempting and deceiving humanity into sin. In reality, this faction of demons are angels that saw their use of God as an abuse of power, dared to dissent, and were banished from Heaven. The angel Lucifer who led their rebellion, now dubbed “Satan”, created a pocket dimension for them to live in safety from the angels’ wrath - this became the Abrahamic concept of Hell. The angels and demons have a tenuous truce: demons accept tainted souls from the angels to punish and purify before returning them to Heaven; in exchange, the angels allow the demons to exist peacefully, and deliver to them the souls of animals and the unrepentant. Without access to God, these demons rely on these souls, which Abrahamic angels deemed unworthy for Heaven, for their energy to survive. This weaker energy has cost some demons their ability to change form, and tainted their appearance to be more monstrous.
Souls/spirits/life force are in fact just semi-sentient energy. Without a corporeal form, they are malleable and weak-willed. Many angels believe that souls of those who have sinned (according to the rules they have set in place or agreed to) are tainted with negative energy and are not safe to feed to God, and so deliver those souls to demons to do with as they please, or to punish and “purify” them before returning them to God. Modern Western demons restore sentience to the souls upon death so that they are fully aware and retain their memories of life, and punish them in the manner pre-determined (and often customized) until the negative energy is dispelled, and returned to Heaven - all at the order of angels.
Angels are all genderless and believe themselves to be above it, but allow mortals to assign genders for their own use (it helps their feeble minds comprehend them enough without breaking, so it’s easier to allow it). Demons sympathize more with humans and often adopt their social constructs, gender included.