"Why would the Eternal Flame punish superfluous prayers instead of just ignoring them, does hearing them at all cost them something?"

"I think the idea is that, well, the entire point of prayer is to provide Them with information about our needs and circumstances as mortals, which is more difficult and costly for Them to seek out from a god's angle. And so, yes, superfluous prayers would cost Them something, if it forces Them to put resources into judging whether the prayer is in fact worth responding to." 

"How does praying work, anyway, what do you do that makes it so your god can see what you're saying - presumably other gods can't, right, and it has to be distinguished somehow from what you normally think or say if it's bad for there to be superfluous stuff -"

"Oh, right, that is worth some clarification! There are many kinds of ordinary prayer that do not unduly attract Their attention; our worshippers, and even priests, are encouraged to pray to Them for comfort and guidance, though those prayers are rarely answered. If a prayer is very important, there is a special ritual to perform first; that part, I am afraid is a closely kept secret, only taught to our priests after their apprenticeship is over." 

"That makes sense, if it'd lead to people bothering them. But they can hear normal prayers, right, how do they do that?"

"I am not sure! Perhaps by something a little like human Thoughtsensing, except from a god's perspective." 

"But how do they tell prayers apart from random thoughts? And do people with shields have to take them down to pray?"

"Prayers have to be - addressed to Them? And to a clear enough idea of Them, that They can recognize - so perhaps it is more like receiving Mindspeech than like reading someone's thoughts directly." 

"If they need help to see what's going on, and prayers have to be addressed to a clear idea of them, do they know what's happening where they aren't worshipped at all?"

"I think much less so! They do have other senses, including Foresight, but - I think They do see much more blurrily in places where They have no followers. ...The theory is that this is true of all gods, and perhaps part of why They appear to have territories." 

"Huh! Because human missionary work tends to move around geographically?"

"It depends, really. Some gods have widespread missionaries and pockets of worshippers all over, whereas others are mostly just worshipped in a particular region." 

"Which one is the Eternal Flame?"

"They are worshipped in several countries, but not literally everywhere." 

"Is that because you haven't had missions in those countries yet or something else?"

"Well, yes, in part because of that - but there is a reason why the Eternal Flame did not advise us to start those missions, even though of course They would ideally want all sentient beings in the world to receive our teachings. They are not all-powerful, and especially in territories where one other god in particular has strong influence, there are god-to-god negotiations involved." 

"So they can't cover the whole world effectively."

"Not at this point in time, no." 

"Will they get stronger somehow? What are the god negotiations like?"

"...I am afraid I cannot say, on either count, I am sorry." 

"Do mortals ever participate in god negotiations somehow, like by - asking people who worship other gods to pray, or anything -"

"Huh! In a way, I suppose, though I would not have thought to call it that. Our priests will sometimes convey messages to priests of other faiths." 

"Like what?"

“Most commonly, if our priests have received a god-Foresight warning of some natural disaster or other dangerous event. But I am sure there are other cases recorded in the books you plan to borrow.”

"How common is getting god-visions of any kind?"