"Well, good thing you know a cleric of travel, then - there's probably a library with an atlas around somewhere, and once I know where it is I can fly there, and then once I've been, I can teleport us. Sounds like a fun couple of weekends. This is a bit of an unusual situation, though, usually I'd be busy with other things and we can say no, in that case, we don't have to offer more help than we can easily give."
"More or less, yep. Maybe a little more of an independent operator than either of those, but that's about right."
"So, gods." And he launches into his explanation. They're a kind of talker, but unlike almost all other kinds, they're fundamentally made of magic, not flesh. In particular they're made out of the fact of a particular thing or group of things - called domains - being important, which is admittedly weird but still true, and answers the question of what it means to be a god of something - it means being made of that thing. Gods' health and strength is tied to the health and strength of their domains, and by nature they're very interested in them in general, so they consider it very important to make sure those domains stay useful, and that people do them well or often. They also often have magic relating to their domains - Fharlanghn can modify the land to make roads and bridges, for example - and can see things relating to their domains if they're impactful enough, even without having a physical body there, and the most powerful gods can see those things before they even happen.
Clerics come at this from a slightly different angle - they start as ordinary mortal talkers who are also very invested in some domain or other, which makes them easier for the god of that domain to see; there's other things they can do to get the god's attention, and if they do, and the god likes them - or if they do that for some concept that could have a god but doesn't, he's not sure why that works exactly - then they'll start getting magic. Occasionally a god will notice someone suitable on their own, too, and give that person magic without them doing anything; it's almost always younger gods with smaller followings who do that. These talkers are called favored souls; they get the same sort of magic as clerics, but with different limitations, and they're generally held in slightly higher esteem than clerics by other followers of their gods.
(Souls are the non-physical part of talkers that persist after death and go to the afterlives. Various sorts of magic interact with them, too. They're a more fundamental part of someone than their physical body, which can be changed in any number of ways or even replaced entirely without changing who the person is - your memories and your sense of morality are part of your soul. Deities and religions often consider souls particularly important.)
Clerics, but apparently not favored souls, can lose their powers if they stop taking enough interest in their gods' domains, or if they act against it; this is uncommon, since clerics are the type of person to be deeply devoted to their domains in the first place, but it does occasionally happen. This means that you can be sure a cleric is in good standing with their god if they can demonstrate magic - though it is still possible to be fooled, if you can't confirm which god the cleric follows. Fortunately most spells require touching a holy symbol of the god they're granted by. (He passes around a copy of Fharlanghn's holy symbol, and drawings he's made of a couple of fancier ones.)
Next: churches. Once a god has clerics and followers, it's usually a good idea to have them work together; they're more likely to be able to accomplish their goals that way. That's what a church is: several people working together in the name of a god. Usually they'll have a building, and do things for the people around them, but how a church works and what it does exactly depends on the god and on the talkers who run it; there's a lot of variance, but they'll commonly hold lectures or other community gatherings to explain what their god thinks talkers should do, do charity work, offer individual advice and counseling, adjudicate disputes, and help coordinate the community to handle threats and problems. Many of them hold ceremonies for welcoming new babies into the community, acknowledging new mate bonds, mourning the dead, and other major life events. They support themselves financially in different ways; almost all take donations, some offer paid services like classes or specialists for hire, some run businesses related to their domains, some are supported by other organizations. Usually there's a degree of internal hierarchy, often with more experienced clerics leading the church and making most of the decisions. "Priest" is a related title, for someone who's involved with the running of a church; not all priests have magic, and not all clerics are involved with a church - Raafi himself is a cleric but not a priest, since Fharlanghn doesn't have churches.
There are also a few other sorts of divine spellcasters, besides clerics and favored souls. Druids are similar to clerics, but devoted to nature; the way to become a druid is a closely-kept secret, though it's understood that anyone with the right mindset for it has a chance to figure it out. Their spells are suited to working with nature and with talkers as creatures rather than as souls, and experienced druids can shapeshift into animals; some gods with nature-related domains will have druids as part of their church hierarchy. Similarly, some gods have paladins, which are a type of divinely-powered fighter; they get less magic than clerics, but other powers that make them stronger in battle, and in addition to losing those powers for losing interest in their gods' domain, they lose them for any immoral act, which makes them suited for positions of very high trust. Paladins most often work with other paladins rather than the general public, in paladin orders, but it's not uncommon for a large church of a god who empowers paladins to have one or two of them working there. Rangers are also a kind of divine spellcaster, with magic similar to druids but weaker; they're only rarely involved with churches, and are most often found in the wilderness, working on their own or alongside druids to protect the natural world.