| Cole Deschain |
Well, ignoring the vast cosmos of many worlds aspect, and just keeping it to Golarion?
Sarenrae by a country mile.
Chief deity of the largest known nation on the planet (not just in terms of its humans, either). A faith that offers things most people seem to need. A faith that makes a point of redeeming its enemies when possible, and it's a lot easier to convert a redeemed foe than a dead guy. Might lose some edge due to being more than happy to let people worship other deities, but also a faith that places few initial demands on converts, but provides enough structure to prevent the faithful from wandering off en masse.
Lamashtu's worshipers, in the main, strike me as not particularly devout. There may be plenty of Orcs, Goblins, Gnolls, and so forth venerating her, but she has no real monopoly on them- although I'd put her at the top of the evil deities for sure.
Abadar has faithful in every settled area- and settled urban regions tend to have a higher population. At the same time though, his faith doesn't seem particularly evangelical- I can see farmers offering the odd prayer in his general direction, but wholesale devotion to him doesn't seem all that common.
Pharasma's church is pretty near omnipresent, but, like Abadar's faith, seems more or less content to stay in its lane.
| Claxon |
Pharasma is the most powerful deity and apparently the one who created this particular iteration of the multiverse (according to one of the latest splatbooks, can't rememebr the name though).
As the goddess of birth, death, and prophecy (although that has likely been broken) she is probably the most widely worshiped and definitely the most important in terms of the universe's continued existence.
| TheGreatWot |
The Concordance of Rivals states that Pharasma was the "Survivor" who inhabited the last multiverse, and created this one after it was destroyed by the Outer Gods. She's grooming a next Survivor for when this multiverse goes under. It makes sense that she'd have the most followers.
I'm assuming that this is what infernal contracts refer to when they say stuff about the "cycle of mortality". Of course, everything written in the Concordance of Rivals, Book of the Damned, and Chronicle of the Righteous is suspect because Tabris was quite insane by the time he returned (or was he?)