Really? You really want to make that statement? Well let's just turn the clock back to the Protestant Reformation... not exactly middle-ages, but definitely closer to it than you talking about the modern church. Oh what's this? Hey, many churches splitting off of the Catholic church and forming their own independent protestant church! How about that.
Chenier, please, think about what you say before you say it... I beg of you.
Even then. The protestant reforms wasn't about all individual pastor changing their church's vocation like they would change what kind of bread they feel like eating that morning.
Religions aren't just a sum of local congregations. And pastors aren't people with absolute moral authority. If all change from the top down was supposed to be 100% accepted by the followers, then there wouldn't have been so much violence between the anglicans and the catholics. Even during the protestant reforms, temples didn't just opt out on a whim, just because.
When anyone tells their followers, whether they be kings, priests, or anything else, that their old practices were wrong and that new practices are justified, they will not be considered to be legitimate by 100% of the following and as such will not have automatic 100% adhesion.
The notion that was being proposed is essentially the opposite of how things are, yet both extremes are poor choices for religion on the long term. Either 1) with the status quo, religions are at the mercy of whoever holds the top rank and thus this scares people away from investing themselves in religion or 2) religions are at the mercy of each unit that makes it up, too easy to dismember and thus scaring people away from investing in things that could too easily be taken away by a seditious unit (be that unit a priest, a lord, or anything else).
Religions need mechanics that are more akin to realms than guilds, with built-in mechanics for governance (like elections), an option to protest out top positions (albeit it being extremely hard to protest out someone who has been leading it for a long time or the founder as opposed to someone who just took power and isn't even a priest), more complex religion definitions (drop-down menu for a variety of traits that categorize religions), heavier realm-religion interactions (national sponsored religions, prohibited religions, tithes, etc.), and so on, priest activities having more bite, and so on.
