From Diablo Wiki
Divine magic is NOT actually an official term used by Blizzard in manuals or other lore to describe magic, but only used by DiabloWiki as a way to group up similar Schools of magic. The term is used to describe Schools of Magic given through divine means, like the high Heavens or the Burning Hells. To fully grasp the concept of Divine magics, it's good to have read about the general nature of magic first.
Divine Schools of Magics
These are the Schools of Magic that DiabloWiki classifies as "Divine":
- Demonic magic - Magic channelled from the Burning Hells.
- Godly magic - Magic channelled from the deity of the subject. Speculative name; could possibly be grouped with Holy.
- Holy magic - Magic channelled from the High Heavens.
- Nature magic - Using nature itself to channel magic energy.
- Spirit magic - Additional magic in the world attached to spirits of different kinds. Not much is known about this source of power. Assumed, speculative name.
Diablo Game Divine Magic
Several Diablo game classes use magic channelled through another entity or source of power. The effects of the magic is very different between types of Divine magic, and are very much subject to the nature of the source.
- Witch Doctor - (Diablo III) This class uses either some sort of Spirit magic/Godly magic, and/or Nature magic in combination with volatile powders that may be chemical, or invoking their gods' powers, or both. He also seem to either get Elemental magic through the "regular" way, or through his gods. Read more about it on the Witch Doctor skills page.
- Amazon - (Diablo II) A melee/ranged class who uses a combination of Prime magic and Godly magic*. Read more about her in the D2 manual or the proper .
- Druid - (Diablo II) The expansion class that changes form and summon spirits of nature for his bidding uses Nature magic exclusively. Read more about him in the LoD manual or the proper .
- Necromancer - (Diablo II) A Caster pet class that seems to use mostly some sort of "Spirit magic". Read more about him in the D2 manual or the proper .
- Paladin - (Diablo II) A Melee/caster hybrid class that completely relies on Holy magic. Read more about him in the D2 manual or the proper .
*Should possibly be called "Holy magic".
Nature of Divine Magic
The word "Divine" is a taken name by DiabloWiki in order to group the magic types that are very similar. It might end up like some other roleplaying system called "Channeling" or a similar name by Blizzard. While the nature of the magic differs wildly between the types (such as Holy magic and Demonic magic), they are given to a being in a similar ruleset of ways: The subject must be dedicated to the cause, and open him/herself to the power. Holy magic requires more dedication, but Demonic magic is likely to rip you to shreds, or give you a few more arms involuntary. Other "Holy" magic is what we call "Godly magic" as a more general term for the deities of Sanctuary, that likely are Nephalem, acting as gods. Nature magic requires an enduring and true friendship, and is possibly related to the Great Cycle of Being which Necromancers study. As for some type of Spiritual magic, there just isn't enough information to classify it or even confirm or deny that such a group exists, yet we have topics such as Life and Death that are closely related to it.
Other Schools of Magic
Arcane magic - Divine magic - Demonic magic - Godly magic - Holy magic - Nature magic - Spirit magic - Death magic - Life magic
Prime magic - Elemental magic - Fire magic - Lightning magic - Cold magic