That's purely driven by the setting (and GM). In the RMSS game I play, we have yet to see any divine intervention. Followers' personalities are suited to their deities, but it's self-selected, not enforced. (I don't know if that would change if someone deviated, or if it will shift as the scope of the campaign gradually widens.) Some of the spells were handed down as traditional songs and chants, for ceremonial purposes, their actual function forgotten. For example, no one (in our region of the world) believed in undead anymore, so the spells for getting rid of them were thought to be purely symbolic. When we actually ran into undead, it turned out they still worked. (On the site we use for game notes, there is a page titled "Things that don't exist." It says "magic orcs undead dragons". But we all know how that last one is going to turn out...)
In other settings, there is a lot more hands-on direction from ones deity.