This is kinda like asking if it's okay that all your characters are murderers.

Sure, it's okay from a literary perspective. There's nothing wrong with writing fictional stories about people who have terrible values. Lots of fictional characters are terrible people.

But is it okay, as in -- is the act morally permissible? Absolutely not. A cursory glance at the central holy text of Christianity reveals a truly despicable set of values that are literally destroying the world. It's all "legally prosecute rape victims by brutally murdering them as a matter of public execution" and "trick other people into being your slaves" and "murder everyone who is different from you." Pretty disturbing stuff in that book. It's weird -- a lot of people like to pretend that it says other things in there, and I often wonder... are they lying to me, are they lying to themselves, or have they just not read the book?