I typically prefer the Eberron approach where there's a focus on faith and practice over the gods themselves. Having gods that objectively exist and can be contacted with relative ease makes religion much less interesting, IMO.
In my setting, Sophian
Ennoism is the most popular religion of the main continent. It is led by the Heptarchy, a religious council of 7 archpriests that claim to be the reincarnations of the founders of the religion (merging the ideas of the
Pentarchy and
Bodhisattvas). They are kind of the "popes" of this setting, and while there are definitely conflicts between the council members and potential for schisms and "pope fights" if they bicker enough, this isn't a pressing concern at the moment. However, the Aasimar city of Avelos has its Angelic Court of 7 archpriests that act as the spiritual/judicial leaders of the Aasimar city-states. They're trying to gain enough influence to splinter off of the mainstream church and become the patriarchs of a new denomination of the faith.
There have been other schisms and heresies in the past that have formed divergent sects, such as heretical Seleranism which claims to be established by the reincarnation of one of the founded saints of Ennoism. And Ennoism itself was founded by 7 saints that split away from a henotheistic mystery cult. Ennoism is thousands of years old and there have been several heroes and other figures in history that have claimed to be the reincarnation of a saint. A player could claim/believe themselves to be one, potentially putting them in conflict with the most powerful religious organization on the continent.
So, I've used this part of the lore to create new religions that could cause conflict between characters, as well as the plot hook of a potential pope fight between the Angelic Court and Sophian Heptarchy to add some political intrigue to the main religion. Players could choose to side with different factions. Maybe one faction is planning on assassinating an Archpriest on the rival council. The players could act as bodyguards for the target, or maybe serve as the assassins. Or they could be sent on a quest to an ancient ruin to uncover some document or artifact that will question the authority of the rival council. The Sophian Patriarchs claim to be the reincarnations of long dead saints. Maybe a unique spell or magic item could determine if that's true. If a paladin believes they're the reincarnation of Zazai the Crusader, or a bard claims they're Daia the Songstress, maybe the Heptarchy sends assassins after them and they're turned away by all Sophian priests.