Okay hear me out, Yandere god x Darling who is pretending to be a priest while scamming people
You come from nothing, your family has come from nothing, and you will likely die with nothing. That is, of course, until you figure out how gullible people are.
It was easy to pretend that you had somehow woken up to find yourself aligned with one of the major gods who presided over the lands. Sure, it was a little tricky convincing people that you were a messenger of one of the deities, but after enough time of tricking people, they believed you. That was when the cash started flowing in.
You made a temple out of the shabby ruins that you used to call home, played the part of a humble servant of a divine calling. People would reward you for every sliver of wisdom or mercy you bestowed, and instead of worshipping at the altar of said god, they left all their offerings to you who claimed to be a vessel.
For the first time in your life, you had food, shelter, people who cared for you and so much wealth you hardly knew what to do.
But in all that time that you had been scamming and stealing from the blindly faithful, you had gained a very amused yet angry devotee: the very god you were claiming to serve.
At first they were annoyed with you stealing attention and worship away from them. They were jealous that you managed to incite mortal beings in a way they had not managed to do in over three centuries, yet here you were, reclining on a throne meant for them. It was almost impressive how you managed to do it. You were determined to save yourself from a fate you did not find suitable, and that was admirable in a way. Though, if anyone should change someone's fate, it should be them not you.
You would be a most successful acolyte in their care, and they refused to give you a choice. You had plenty of time to give them the prayers and devotion they had demanded in scripture for nearly thousands of years, so you should not be surprised when you wake up one morning to find that you're now actually aligned with the god you'd been using to scam people. It seemed that all this effort had been simply to give them the best offering they'd had in a millennia: you. It's be best if you actually started to worship them properly now, yes?