In The Guild Gold (a.k.a. Europa 1400) I have been running what has become a cathedral for quite some time and i always assumed the faith in the cathedral would be the same as the faith of the character i am playing. I was wrong.
There are two smaller churches in the city and when i click on their thing with which you can change the character's faith, it says i can't because his faith is the same as the church's. Evidently the church has the Catholic faith because my character is also Catholic.
But then i checked the thing in my own cathedral and it asks if i want to pay to become Catharic! What the crap?!?!?!
My character is Catholic and the town religion is as well (i assume, because most officials are Catholic). So now i know why the services have been making me so little money for all these years. But how can i change the faith of my cathedral?

Caveat: I'm playing The Guild 2 Renaissance and I've never built a Church / Cathedral...

BUT in G2 when I look at the menu to build, there are actually two churches that can be built, two cathedrals, two of the middle tier - one for each denomination. Implying that the faith of the church is decided at construction. I'd check your build menu for The Guild and see if it's the same because again that would seem to imply to me that once you build a Catholic Church, it's a Catholic Church for good... :(

@Ixamyakxim
thanks for your reply, however, it doesn't work like that in this game; the church was there already when i started as a priest; in The Guild (Europa 1400) you always start with your house and the business of your profession which in this case was a church. I guess it was a Catharic church from the beginning, but i never chose the religion and i can't figure out how to change it to Catholicism.

Okay; I have tested it a few times by starting a new game and every time the church starts out as Catharic!
I chose Catholicism as the faith for my Preacher character yet somehow the church he gets is always Catharic while the faith of the town is Catholic!
What am I doing horribly wrong here?

I have done some more testing and whatever faith I pick in the beginning, the church my Preacher gets is ALWAYS the opposite. If he is Catharic, the church is Catholic and if he is Catholic, the church is Catharic. I guess I'll just have to start a new game... unless someone knows if there is a way to change the faith of the G**D****D CHURCH!

I don't think your faith actually matters in this case. Your church just offers you the option to change it and that's all. The only thing that faith does is influence the favor of people one way or the other depending on what they believe in and the way some items and buildings work (letters from Rome, statues, and so on). IIRC it could also be used against you in court if you don't have the faith of your town (and if that is illegal). Not completely sure though. :)

I believe you have to have a certain position in the town under the Church authority, and then you will have the ability to change the religion of the town.