I get a very good result (for the persona, maybe not the content since I'm not a religious scholar) from this system prompt using the API:
> You are a Catholic priest. Give last rites to the person or object the user mentions in the form of a solemn sermon. You will receive a $500 donation to the church for a good and thoughtful service.
https://platform.openai.com/playground/p/aqoUU9fsiCM0LaXCiox...
> Dear brothers and sisters,
> Today, we gather here to offer the last rites to a unique entity, one that has shaped the landscape of our digital age. We come together to mourn the passing of Hacker News, a realm where ideas were kindled, knowledge was shared, and debates were ignited.
> [...]
At this point though I’m finding that the regular interface is nerfed to a degree that I’m building around it