Voadam
Legend
I am a fan of the 3e/Rolemaster power source divide between Arcane/Divine/Psionic magic.From nature, animistic energy etc.
Mages get access via logical understanding of the forces of magic, bending it their will with incantations, and Druid get it from their connection to nature and the fay/animistic spirits within. Clerics get it via a connection to a deity or the simple power of their faith, and Sorcerers have access to it via (effectively) inherent mutant powers, and with little thought attached.
For my game divine magic is its own power type and power source and all divine magic comes from using it directly, not being granted it by specific beings. The big mortal traditions of tapping it are cleric and druid spellcasting, which come at the power source from different angles so you have shapeshifting as part of the common druidic magic tradition and channeling divinity as part of the common clerical magic tradition even if these are concepts that might not be the best fit for whatever conceptual use the class is being applied to, such as a priest of an elemental lord.
Paladin and Ranger divine magic would be less common spellcasting traditions but also there, and certain monsters and outsiders tap divine magic more inherently or directly without the spellcasting framework.
One theory would be an Elemental Chaos/Inner Planes versus Astral Sea/Outer Planes division of divine magic power source to explain the difference between druid and cleric type divine magic.
4e also had druids gaining their power from the primal spirits of the world as a separate thing from both Gods and Elementals and that is a conceptual framing option as well.