Cleric: We believe you sold your soul.
Celestial warlock: Well, yes. To your god.
Cleric: That's unethical! You should be ashamed of yourself!
Celestial warlock: So does that mean you worship someone inherently unethical or was he just unethical when he bought my soul?
Cleric: ...
Celestial warlock: You're just jealous because he doesn't let you shoot energy beams at will, right?
Cleric: Damn straight I am!
Broke: selling your soul for a 1d10 Cantrip
Woke: selling your soul so you can talk to your dog
tbh I don't like the trope of "pact with a devil = you sold your soul". At least in the first instance, even very desperate people are usually not desperate enough to literally sell their soul. Not in a world where you know that souls are very real and selling it has eternal consequences.
Most often, a pact entails something much less. A favour of some sort, either a specific negotiated deal, or a general agreement to do "something" in the future (think: the Minor and Major Boons from Vampire: The Masquerade). That goes whether we're talking about a warlock pact or some other pact.
Heck it doesn’t even have to be a “deal”. I’m sure at least a few entities (Archfey, maybe) would grant magic powers just to see what happens. Sort of like the Outsider in Dishonored.
From description of the Great Old One pact:
The Great Old One might be unaware of your existence or entirely indifferent to you, but the secrets you have learned allow you to draw your magic from it
Patrons can have whatever motivation or lack of motivation the DM wants. I personally like there being some kind of RPing effect. Maybe some task you have to complete, punishment for acting against your patron, slowly eroding sanity. But none of that is necessary.
"Sell isn't the word I would use... Lent. I lent my soul. For a few hundred years. That's all."
