I’ve been thinking.
How does religion actually work in this world?
The most widespread religion seems to be the very generic “The Light”
But what IS “The Light”?
Is it a god? Literal light?
Other religions are more straight forward with Tauren having the Earth Mother, Shamans have “de spirits” etc. etc.
But then there’s the incredibly imprecise “The Light”
Given all the retcons - including/especially the edgelord stuff they added in Legion and BfA, I’m not even sure the devs themselves know what the Light is or what it stands for anymore. I have a few theories, though.
This applies to everything in the setting btw.
a raid boss
The Light is a force of endless energy within the Warcraft Universe, one of the two most fundamental alongside the void. This is what the various paladin orders with the exception of the Zandalari Prelates, and the priest orders bar the Cult of Forgotten Shadow use as power. Shadow Priests, obviously use nothing but void. Discipline Priests use both light and void.
( Priests/Priestesses of the Moon / Seers / Sunwalkers / etc all canonically use holy light, except they just call it through different means such as Elune or An’she causing it to look different. Prelates use the power of the late loa Rezan, who’s power is -similar- to the holy light enough to where Prelates can be compared to Paladins.
It is not a god, it 's basically just… light. It is not sentient or an individual at all. There are beings -of- light such as the Naaru but the Light itself is not a sentient entity. Using it and being around it effects and invokes feelings of the heart; hope, courage, and comfort.
But there are NPC that claims the Light speaks to them and some such
My understanding is that, per Tyrmak’s explanation, that’s basically just their underlying feelings resulting from the use of Light magic along with some basic abilities of telepathy and divination that the Light is capable of.
The opposite of darkness.
Those NPCS are inaccurate, because of as Twinkletorch said, their underlying feelings as a result of the use of Light magic and/or it is something else that is of the Light that is speaking to them entirely that is a sentient individual (eg; Naaru) or those NPCS are getting manipulated & tricked by something that isn’t of the Light at all (eg; Abbendis)
Thus far none of the mainstream faiths codify the Light as a cognizant “person” who speaks to the faithful; when a character believes it to be the case, they’re generally considered crazy, and turn out to indeed be so and/or under the influence of something else posing as the Light. Per Tyrmak’s citation, when Abbendis starts receiving actual cogent instructions from “the Light,” both the Argent Crusade and the Scourge write it off as symptomatic of her being insane. And rightly so, because she’s both thoroughly unhinged by that point and actually receiving said instructions unwittingly from the dreadlord Mal’ganis.
Visions and inspirations derived from the Light’s power aren’t really presented as outright instruction from an entity unless they’re being projected by an intermediary like a naaru. Velen himself says that he receives tons of visions from the Light and that most are merely possibilities. He has to sort through them with his own wisdom and feelings to determine which ones are actually the truth of what is, was or will be and which ones are merely potential events that may or may not contain some other wisdom from observing them but aren’t actually the true way things happened or will happen.
In the time of Warcraft Orcs & Humans and Warcraft II, humans were mentioned as worshipping a god, and believing in angels and demons. Now, they simply worship the Light, a cosmic force created by the First Ones. The Light as also referred to as the “spirit of humanity.”
The Light is a cosmic force that can utilize necromancy to raise the dead. Isn’t new lore fun?
The Light is among the many kids who are constantly bullied by The Void. On a daily basis the Void steals some kid’s lunch money, beats them up, and then makes a habit of eating lunch in front of everyone. He likes to be in charge and even scares all the rival bullies such as The Legion and The Mawsworn.
The Light often tries to lead counters against The Void in the name of justice.
However, deep down, The Light longs to be the grand leader of everyone and is not above bullying people to conform to his ways.
The Mawsworn aren’t scared of the Void. The Void is scared of the Mawsworn as well as the Darkness brought about by the Crown of Light claimed by the Golden One.
Don’t forget that Sylvanas after having her Soul damaged by Frostmourne had her Emotions slowly dulled by a Darkness that was at risk of making her less inclined to aid the Jailer. Why should the Helm of Domination be any less tainted by Darkness even after turning into the Crown of Wills?
Her attacks despite being amped by Anima also did not match any of the Dark Magics that Jaina seen and she had encountered both Void(used by Old Gods & Voidwalkers), Shadow(used by Nathrezim & Mueh’zala), Fel(used by the Legion) & Death(used by Scourge and the Denizens of the Shadowlands) Magics!
The Death Magics of the Mawsworn were recognizable enough for Thrall to recognize them as being similar to the Necromantic Magics of the Shadowmoon Clan(which says more about how the Nathrezim influenced the Void Lords than about the Mawsworn Death Magics).
The Void scares the Legion but in turn is scared by the Darkness and Mawsworn.
The Mawsworn lost yet it seems the Darkness is winning via subtlety.
This makes me wonder… where do the Naaru get their visions from? Do they conscious peer into the future? Does it happen at random times?
Wait. What is “Darkness” if it’s not the Void? I thought they were the same thing. 
Both N’Zoth, Il’gynoth and Ra-den treat the Darkness as something they dread.
Furthermore the https://wowpedia.fandom.com/wiki/Everliving_Statuette_(item) says:
The seventh covets what the six hold fast. The fulcrum wavers. All will be undone.
Firim also mentions a seventh Cosmic Force that represents a Solution awaiting it’s opportunity.
https://wowpedia.fandom.com/wiki/Firim_in_Exile,_Part_7
Similarly he mentions both a Thousand Truths and One Truth being uttered in the Oracles’ Song at once:
https://wowpedia.fandom.com/wiki/Firim_in_Exile,_Part_6
Logistically the 6 Cosmic Forces are a Thousand Truths while the Darkness is One Truth.
Light provides many opportunities with Absolute Certainty, Shadows of the Void provide many opportunities as well, Life provides many opportunities, Death provides many opportunities, Order provides many calculations and Disorder provides many possibilities.
Darkness leaves only the moment. The One True Path is forward with no choices offered to you leaving you with only yourself.
Ra-den says something really interesting in the Throne of Thunder raid.
There is a yawning chasm of darkness beneath you, mortals. Vast, endless and all consuming. I do not believe you can correct this doomed course.
It’s why he’s clinically depressed.
What do you think it means. It can’t be the Maw, technically the maw is above us not below us. The only thing below us in the core is Azeroth.
He seems to be restored when taken by N’Zoth. claims that the Titans one true path is to blame not the Void.
It was bound to happen. We had known for a while that other cosmic forces could raise the dead. Not just death magic. Fel could do it, e.g. Mannoroth in WoD. Void could do it, e.g. AU Ner’zhul in WoD. Life magic could as well such as the Primals in WoD. Raising dead orcs and controlling their bodies like puppets on strings, well vines. We have yet to see the Arcane do it. But we know that the Arcane can be used to extend someones lifespan beyond what it should be. As it can manipulate time itself. From the Night elves via the Well of Eternity and later Nordrassil to Agewynn, a guardian of Trisfal. Who lived for well over 1k years. And that was a thing all the way back in WC2. She basically lost her powers of the guardian by giving birth to Medivh (as intended) and what was left when she brought him back to life just in time for the Third War.
I always took it to mean Y’shaarj and how the Old God is THE physical manifestation of negative emotions. Ra let his despair over the Titans deaths consume him. Remember, like Shaohao we had conquered 6 of the 7 sha at that point. But even we had no knowledge the Sha of Pride until Shaohao himself told us afterwards.
highly doubtful he meant the maw. The Maw probably wasn’t a thing conceptually until like late Legion / early BFA.
We actually have an example of arcane undeath in the form of Meryl Winterstorm (these days called Meryl Felstorm), an undead mage who’s kept himself that way with his arcane power.