A Priest and a Warlock walk in to a bar.
The Barkeep yells “We don’t serve your kind here!”
Who walked out of the bar, and why?

The popular perception is that a Priest and a Warlock are not the same thing. They are enemies, with the Priest being presented as “pure” and the Warlock as “tainted”. One is perceived as trustworthy and respected, while the other is perceived as villainous and reviled. A building with mass seating for the faithful is supplied to the Priest while the Warlock is generally relegated to a backroom with a handful of followers. Inevitably the concept of good/light, is attributed to the priest, where as the Warlock is evil/dark. The first has a religion, the second has a cult. How much of this dichotomy is strictly better marketing by one side over the other?
Both the Priest and the Warlock are intrinsically powerless individuals. They can belong to any sentient species. Both are historically male, with a female Priest being a Priestess and a female Warlock being a Witch. In this article gender is not relevant and will be treated as neutral. Unless they are provided arcane knowledge to allow the use of magic, or they are supplied the knowledge to use the power of nature, both the Priest and Warlock must settle with wielding the powers of other worldly entities. In the case of the Priests it is a god, a celestial entity with omnipotent power within the scope of its purview. Where as the Warlock employs the powers of other celestial entities, which may be gods, or may be some other supernatural entity, but are assuredly not socially revered, in the same manner as gods.

Most societies treat Priests and Warlocks as complete opposites. But are they really? Upon closer historic scrutiny, many Priests have been very bad people, and many Warlocks have been helpful healers. One is lauded for the benefits they bring to the society, and the other is held to account for crop destroying weather. But which is which in this situation?
Both are sentient beings who depend on powerful other worldly celestial entities, and hope they do not say, or do, the the wrong thing at the wrong time. One source is called holy or divine and the other is called dread or infernal, but both sources will cut off the power without notice. A missed prayer or sacrifice, perhaps a broken vow or flubbed ceremony, even a poorly timed ill-advised comment, all can cause serious trouble. In both cases, blasphemy is less about good or bad and more about upsetting the boss.
Translation for invisible authoritarians is the position of these individuals. Priests proselytize at length of the desires of their god, in exchange they gain the authority to use the powers of their patron. For Warlocks it is to follow the instructions of their contract, in exchange the Warlock gains the authority to use the powers of their patron. Both the Priest and the Warlock swear only they understand their sacred text’s intentions, because these texts are communications from their supernatural entity. Should the message be misconstrued, the blame seldom, if ever, lands on the appropriate higher power.
Rules and compromises control every part of these individual’s lives. Priests follow holy texts, doctrines, and traditions to display their faith. Warlocks must follow the rules of their contract, or contracts, which may include prayers, sacrifices, and rituals. The rules for each may be different on what may/must beaten and when. The one thing that is clear, ignoring or breaking these rules can have dire consequences. Call it divine justice, retribution, or just contractual enforcement, breaking these rules leads to serious punishment. Blasphemy is the term for failed obedience.
The price to be paid for the inclusion in both of these paths is sacrifice. Priests give up wealth, sex, worldly possessions, a normal life, and their soul, to be able to wield the moral authority of their god. Whereas a Warlock may sacrifice all of the same, or may have other options in their contract, or possibly multiple contracts, in order to wield supernatural powers. Both the Priest and the Warlock swear the exchange is worth it for the powers received and the works that they can perform. Each will often warn others against attempting the same path, for there are many pit falls and difficulties involved. After all, power is never cheap.
Rituals and trappings are where the similarities intertwine. Priests recite prayers, wear symbols, and vestments. They do so while enacting ceremonies that are not to be disturbed or questioned. Similarly the Warlock chants spells, draws sigils, and follows exact ritual steps that cannot altered. The point of all this pomp and circumstance is to reinforce that asking too many questions in either setting will risk accusations of doubt, heresy, or blasphemy. The silent follower is, after all, what keeps both systems running smoothly.
Priests and Warlocks differ mostly in popular perception and manufactured reputation. While the Priest is praised for their obedience to their god, the Warlock is condemned for the same. Both serve unseen supernatural entities. Entities that have ulterior motives they do not share with the general population or their followers. Both the Priest and the Warlock live by the strict code of their contracts with these entities and fear stepping outside their confines. Call it faith or contractual obligation, they are the same, deviate from the path and the blasphemy may offend the being holding the leash.
So who walked out if the bar?
Both.
The bar was “Auðumbla‘s“.
– Dru