The Sacred Darkness

""Those who live in the shelter of the Most High will find rest in the shadow of the Almighty.""

- Psalm 91

This trope is basically the ultimate logical conclusion of Dark Is Not Evil. It usually manifests in the powers of The Dark Side being treated as equal (or even better) compared to the powers of light, coming with the same acknowledgement and worship that people offer to the Light. It may still be treated with suspicion or fear by the common people, however, since this trope rarely excludes that Dark Is Evil.

Usually, this kind of darkness takes the form of a "pure" darkness as opposed to the "corrupted" darkness that is typically used by villains. The philosophical interpretation behind this is Dark Is Not Evil taken to extremes, where it is acknowledged that light and darkness can and must exist only simultaneously. Darkness can still be associated with aspects such as death, but expect this to be treated in a somewhat positive way, such as death being an important part of the cycle of rebirth, being natural and therefore being necessary for the world. Also, a dark god may simply be doing an unpopular, but still very important job, rather than being a villain. This kind of darkness may not be nice, or comfortable, or maybe it is even outright terrifying, but it nontheless radiates a dignity that cannot be denied and, like it or not, you know that the world would be worse off without it.

"Pure" darkness powers can often easily be distinguished from their "corrupted" counterparts. An Instant Kill spell by a corrupt villain would likely involve a lot of pain, mutiliation, brutality etc., while a pure darkness spell of that kind might result in something resembling a peaceful sleep or simply dropping dead. Pure darkness powers tend to avert the more obviously negative aspects of darker powers such as Mind Rape, Cold-Blooded Torture and somesuch and instead tend to be more spectacular and flashy, or involving beautiful stuff, like conjuring up the star-filled night sky, or awesome stuff like summoning a black raven to attack the enemy. For instance, if a hero's signature move was a combo attack where he cloaks his blade in light magic, a "pure" darkness counterpart to that move would simply involve cloaking the blade in shadow instead.

Despite this, it may still carry some of the usual problems of dark powers, such as the Noble Demon spirits empowering the Sword of Plot Advancement deciding that their user is not worthy enough to use their sacred sword and killing him, or simply the usual problem of prolonged exposure to the darkness being dangerous to the mind. Note that "sacred" does not have to equal "good". More often, these characters embody a morally neutral concept or ideal. On rare occasions, villains can use The Sacred Darkness, but usually this only works when they are opposing another villain who is using the corrupted variant in a A Lighter Shade of Black situation.

Can also be interpreted as necessary and holy when its part of a Yin-Yang Bomb. In a similar vein, the pure/corrupt interpretation can be done for Light in a Light Is Not Good scenario, such as a "corrupt" light spell that poisons the enemy.

Note that this trope is not just Dark Is Not Evil. The usual variant of said trope is that a good person is using dark powers despite their villanous and problematic ways for the sake of good. That is not really this trope. This trope is about some kind of darkness that exists in a form where you can reasonably justify its existence for the good of the world or when darkness is treated in some way as equally as holy or good as Light would be treated. Generally, if your hero can make a somewhat logical World of Cardboard Speech, a Reason You Suck Speech or simply a Rousing Speech involving the virtues of their particular brand of darkness, it qualifies. Similarly, if following this darkness has a bit of a Right Makes Might feeling to it, it would also count.

Anime and Manga

 * Digimon Frontier: Kouichi embodies this and also nicely illustrates the change between "corrupted" and "pure" darkness; he starts out Brainwashed and Crazy using a twisted set of Darkness spirits - the creepy, borderline-Eldritch Abominations Duskmon and Velgmon - and upon undergoing a Heel Face Turn, the spirits are purified into the Black Knights Löwemon and KaiserLeomon, the embodiments of the sanctity of the element of darkness.
 * Given that it turns his eyes from the more aggressive red into an honest green and gives him wings, one might argue that Beelzebumon of Digimon Tamers - who is in the broader canon one of the Seven Great Demon Lords - goes through a "dark purification" as well when he obtains Blast Mode. Similarly, his Digimon Xros Wars incarnation (which is very similar to Blast Mode) is an outright holy warrior, being reborn into that form using a mask of the goddess he once served, and is one of the noblest and most loyal characters in the series; whenever he DigiXrosses with Shoutmon, the end of the sequence plays a brief high note of a Cherubic Choir.
 * Kara no Kyoukai:: Ryougi Shiki uses the Mystic Eyes of Death Perception, a very rare and unique power that allows her to see the inherent death of all things. Essentially, this makes her the human personification of the Grim Reaper. Nontheless, she is good enough to serve as a hero for this story and to get an almost holy-sounding Theme Music Power-Up. It helps that.
 * Hayate Yagami of the Lyrical Nanoha franchise holds the title "Queen of the Night Sky" and is the heiress to the Book of Darkness' power, as well as the only mage in canon who can use elemental Darkness to power her spells. However, she is also the Big Good and nobody minds her darkness much, neither magical, nor inner.
 * In Nanoha As, there is even the "pure-corrupted" dichotomy: the old Book of Darkness (or rather, parts of it) is "corrupted", while Hayate herself and Reinforce are "pure" Darkness. It is strongly implied that the Book itself was "pure" Darkness upon its first creation but It Got Worse along the way.
 * More specifically. It was originally called "the Tome of the Night Sky", and was simply a repository of magical knowledge. Being such a thing, various douchenozzles over time took to obtaining that knowledge for the usual reasons evil people would seek it. Their manipulations, across time, resulted in the Book becoming corrupt.
 * In Yu-Gi-Oh GX, the Gentle Darkness not only is a force for good, it's what actually created everything in the first place. This isn't commonly known information, but it's true nevertheless.

Literature

 * Chronicles of the Emerged World: One of the Eight Lands is the Land of Nights, which is costantly covered in eternal darkness. Nevertheless, the darkness is also one of the eight sacred elements needed for the Talisman of Power, and the spirit of darkness is the kindest and most helpful. By contrast, the Light spirit Glael comes across as a Psychopathic Manchild who's willing to resort to Demonic Possession to end his solitude.
 * Toyed with in Book 7 of The Dresden Files, Dead Beat, in which Kumori claims that Necromantic magic (Always Chaotic Evil) can be turned to good purposes (such as when she brings a recently dead man back for long enough for the paramedics to save him), as ordinary magic can be turned to evil, her reasoning being that if death is defeated, the genii of history could live for ever. Harry considers this for a moment, then points out how close this is to Jumping Off the Slippery Slope.
 * Explored in the Dragonlance novels, pertaining to the different mage orders of White, Red, and Black. At least one character wonders why the "good" mages allow the Black Robes to exist in their order, and it's explained that darkness has its own purpose and that there must always be a balance; tipping the scales either way leads to catastrophe, and in fact, the Cataclysm that devastated Krynn was caused by the Kingpriest trying to tip the scales towards the side of "light"; the same applies to priests, since the evil gods need worship just as much as the good gods. Also explored by Crysania in "Time of the Twins" in the same series, when she muses that fear of the darkness is childish and stupid, and that lighting candle after candle to keep the darkness at bay only results in a house burning down because people can't understand that the darkness has a purpose.
 * The Dwarfs of the Discworld, being belowground-dwellers, have many values opposite to those of humans. One of them is that they consider darkness sacred, and their equivalent of priests keep themselves in it whenever possible, many shunning daylight altogether and believing it to be blasphemy. Part of the Dwarf Creation Myth goes: "The first Brother walked toward the light, and stood under the open sky. Thus he became too tall. He was the first Man. He found no Laws, and he was enlightened. The second Brother walked toward the darkness, and stood under a roof of stone. Thus he achieved the correct height. He was the first Dwarf. He found the Laws Tak had written, and he was endarkened." This said, however, Dwarfs recognise that there are many kinds of darkness, and some, such as the Summoning Dark, are malevolent.
 * Taken to the extreme in the Black Jewels Trilogy and subsequent books. In-world, the Darkness is the source of the characters' power, receives the characters' prayers, and inhabits the Abyss. As an extension of darkness being one of the most positive traits, possessing a darker Jewel confers a higher position in the society's hierarchy.
 * In The Lord of the Rings, Tom Bombadil (the oldest being in Middle-earth) mentions that he "knew the dark under the stars when it was fearless--before the Dark Lord came from Outside". The association of the starry sky with Elves and the Elder Days ensure this trope is always in play in Tolkien's works, even though Morgoth and Sauron are textbook examples of Dark Is Evil: this is an example of the "uncorrupted darkness" idea.

Religion

 * This trope was also true for several religions, such as various myths about the Moon. Gods of death, afterlife etc. also occasionally qualify.

Tabletop Games

 * In Warhammer Fantasy Battle, magic is either present in it's raw chaotic form, or is refined into eight winds (which can be further refined and weaved together into High Magic); one of said winds provides magic over death, and other over shadows. Both are very distinct from the chaotic magic used by necromancers and worshippers of chaos gods.
 * In Magic: The Gathering, while Black magic is often focused on unpleasant things like necromancy, corruption, selfishness, and Mind Rape, it is not inherently evil, and also encompasses necessary forces such as death and self-preservation. Not only have some protagonists been pure Black but, like all colours of mana, Black necessary for planar stability.
 * R. Talsorian Games' Cyberpunk supplement Home of the Brave. A religion called Worshippers of the Night considers the night to be a time of rest and spiritual purification. They patrol the streets at night to "protect the night's holiness against the evil that surrounds us."
 * In the Mystara setting of Dungeons and Dragons, the Immortal (Immortals being the D&D functional equivalent of AD&D's gods) Nyx was the Entropic Immortal of darkness, night, and the undead. She is also pretty much the only Immortal of Entropy who is not evil, although her goals would be horrifying to most people. Still, Nyx serves as the key reminder that Entropy is as necessary for the existence of the cosmos as are the other four Spheres of Power, and is not inherently evil.

Video Games

 * Fire Emblem: Several of the holy Infinity+1 Swords used by the Precursor Heroes and eventually obtained by the player are dark magic tomes, but are treated with exactly the same level of reverence and usefulness as the other holy weapons; said weapons are Apocalypse and Gleipnir. The exception here is the Jugdral canon, which plays Dark Is Evil very straight - of the holy weapons of the Twelve Crusaders, none of them are dark magic, and the equivalent dark tome, Loptous, was born of a destructive evil god of the same name and is used by the final boss, a descendent of and possessed by said evil god; however, the "holy" blood of Loptous is charted in exactly the same way as the holy blood of the Crusaders. Nontheless, the holy sword Mistoltin might be an example, as side materials sometimes call it a demonic sword and its destined wielders are always Black Knights.
 * Kingdom Hearts skipped into this occasionally. While usually Dark Is Evil and Light Is Good, some parts of the story regarding Riku have felt like this, especially in Chain of Memories, where he's told to accept his darkness and uses it to beat Zexion.
 * King Mickey outright tells Xemnas that the Worlds are made of both Light and Darkness, and that "you can't have one without the other."
 * Shining Force. The Sword of Darkness, despite being a cursed weapon, might count as this, since it's needed to form the Chaos Breaker.
 * Heroes of Might and Magic V has the dark elves, who worship Malassa the Dragon of Darkness, and the necromancers, who worship "death" aspect of Asha the Dragon of Order. Both ultimately work for the "good" side in the campaign.
 * The Umbra Witches in Bayonetta are the counterparts of the Lumen Sages but are not presented as evil as such, even though they get their powers from a Deal with the Devil. The two clans paid each other great respect (before they started waging war to each other, that is) and each one protects one Eye Of The World. These "Eyes" represent Darkness and Light and are both necessary to awaken Jubileus.
 * In Illusion of Gaia, the hero exclusively wields dark powers, while some of the monster he fights used to be human before they were touched by the light of an evil comet.
 * In Ocarina of Time, the Sage of Light sends the hero on a quest to awaken the Sages of Forest, Fire, Water, Shadow and Spirit, all forces of good required to defeat the Great King of Evil. This theme is further explored in Twilight Princess, with events such as the Blade of Evil's Bane being blessed by the gods of the Dark World.
 * In Luminous Arc, the Twilight Witch is of the Luminous Church. Her powers of Darkness counterbalance the Dawn Witch, Lucia's, once it's revealed that the Witches are not evil.
 * In Universe At War, the Masari are masters of both Light and Dark. They advocate maintaining a balanced vision above all else and are definitely not evil. Their Light powers give offensive buffs (extra damage to enemies over time) while their Dark powers boost defenses (Dark Matter Armor, a self-regenerating second health bar).
 * The Undead element serves as this in Skylanders: Spyro's Adventure. There are references to the undead attacking the living, but some have shown themselves to be friendly; plus the Eternal Undead Source is one of the components of the Core of Light, and the Skylanders themselves include a number of Undead members (even if one is a Token Evil Teammate and people are wary of the dark powers of two others). It should be noted though that while undeath is all right, darkness is still portrayed as evil.

Web Comics

 * The orc gods of light and darkness in Dominic Deegan are supposed to form a balance of death and rebirth - bad things happen to both when it is disturbed.

Western Animation

 * My Little Pony Friendship Is Magic has Princess Luna, who is essentially the Physical Goddess of the night. Her sheer frustration at her subjects' failure to understand that Dark Is Not Evil actually turned her evil for a brief period (one thousand years counts as "brief" in divine terms); her job of making the night fall was so justified in its existence, however, that her sister Celestia, responsible for the sun, took over the job of bringing the night into existence as well after Luna's banishment. In the present day, however, Luna has returned, and presumably has taken to her duties once again. It helps that, according to backstory, both Celestia and Luna stood up together against Discord, essentially the god of chaos, by wielding the Elements of Harmony.