A number of deities claim arcane magic as their domain, for magic is as much a part of the fabric of the cosmos as wind, fire, lightning, and all other primal forces. Just as there are deities of the sea and gods of warfare, the arcane arts feature their own divine patrons.
Such deities often have clerics, but many gods of magic bid their followers to take up the study of wizardry. These religious magic-users follow the arcane tradition of Theurgy, and are commonly known as theurgists. Such spellcasters are as dedicated and scholarly as any other wizard, but they blend their arcane study with religious devotion.
Sources: Unearthed Arcana 34 - Wizard Revisited
When you choose this tradition at 2nd level, choose a cleric domain from your chosen deity’s list of eligible domains. The Knowledge and Light domains are especially appropriate choices for a theurgist.
Beginning when you select this tradition at 2nd level, whenever you gain a wizard level, you can replace one of the wizard spells you add to your spellbook with a cleric domain spell for your chosen domain. The spell must be of a level for which you have spell slots.
If you add all of your domain spells to your spellbook, you can subsequently add any spell from the cleric spell list instead. The spell must still be of a level for which you have spell slots.
Any cleric spell you gain from this feature is considered a wizard spell for you, but other wizards can’t copy cleric spells from your spellbook into their own spellbooks.
At 2nd level, you gain the ability to channel arcane energy directly from your deity, using that energy to fuel magical effects. You start with two such effects: Divine Arcana and the Channel Divinity option granted at 2nd level by your chosen domain. You employ that Channel Divinity option by using your Channel Arcana ability.
When you use your Channel Arcana, you choose which effect to create. You must then finish a short or long rest to use your Channel Arcana again.
Some Channel Arcana effects require saving throws. When you use such an effect, the save DC equals your wizard spell save DC.
Beginning at 6th level, you can use your Channel Arcana twice between rests, and beginning at 18th level, you can use it three times between rests. When you finish a short or long rest, you regain your expended uses.
If you gain additional Channel Divinity options from your domain, you can employ them by using your Channel Arcana feature.
Channel Arcana: Divine Arcana
As a bonus action, you speak a prayer to control the flow of magic around you. The next spell you cast gains a +2 bonus to any attack roll you make for it or to its saving throw DC, as appropriate.
At 6th level, you gain your chosen domain’s 1st-level benefits. However, you do not gain any weapon or armor proficiencies from the domain.
At 10th level, you gain your chosen domain’s 6th-level benefits. Your faith and your understanding of magic allow you to delve into your god’s secrets.
Arcane High Priest
At 14th level, you gain your chosen domain’s 17th-level benefits. Your academic nature and understanding of magic and doctrine allow you to master this ability sooner than a cleric of your domain.