If this is true, it is annoying. I don't see why I have to automatically purchase them when my religion is already flourishing and not in need of help. All those science buildings that I'm planning on faith-buying really add up and I NEED faith for them.
Seems more like a bug than a mechanic, especially since I clicked an option to not have them auto-purchased.
It seems like a way of limiting the ability to hoard Faith until Industrial and then mass buying GS and GE. Whether you agree with this design decision or not (personally I like the way you can't stockpile faith in the early/mid game as you have to make pressing and difficult choices on what to spend it on) it is working as intended.
Faith you've accumulated will automatically be spent on spawning a Great Prophet once you've reached a certain threshold (to see this hover your mouse over the
The first turns it's very easy to capture cities if its ungarrisoned, just a hit or two from a cannon, and voila. Later on I had 6-7 cannons beseiging an ungarrisoned city for 5-6 turns to be able to take it. Now I'm beseiging Washington from across the river with two rifled cannons and four standard. However, that is not not nearly enough as it heals up to full in one turn... especially when I have to use a cannon or two to sink embarked units every now and then.
I thinking that I would raking science with observatory in mid-game if I done that.