Question

How many cults and religions are there? I'd like some information about each one, like what or who each one worships, what's their main location, where can we find books and other information about them...

Answer 1

In Tibia there are many cults and religions, even some may not have a name per se, but I will name the ones I know or remember so far:

1. Followers of benign Gods.

• Uman, Fardos, Bastesh, Suon, Kirok: In this religion we find mainly humans.
• Crunor: Followed by elves and druids, usually the people of Carlin.

2. Followers of evil gods.

• Zathroth: Ferumbras, Demons, and other creatures and humans.
• Fafnar: Mainly Necromancers, Circle of the Black Sphinx and some Druids from Carlin.
• Urgith: Necromancers.

3. Followers of Demigods / (supposedly) ascended entities / powerful or important entities.

• Variphor: Yalaharis, Cults of Tibia creatures, Shiron'Fal, Demon Princes, Zoralurk, 1 Ruthless Seven member (probably Ashfalor or Bazir), Warzone creatures, interdimensional creatures and more creatures/NPCs throughout Tibia.
• Banor: Humans in general, more prominent in Thais.
• Daraman: Humans from Darashia, Nomads and blue Djinns.
• Durin: Dwarves.
• 7 Celestial Paladins: Elves.
• Ferumbras: Demons.
• Goshnar: Necromancers.
• Snake God: Lizards
• Qjell: Deeplings.
• Arkhothep: People of Ankrahmun.
• Tha'kull: Minotaurs.

4. Followers of probably non-existent deities/entities.

• Chyll: Barbarians
• Bong (holy ape): Apes

5. Members of Cults or Cabals:

• Triangle of Terror:  Made up by 3 Demons (Zoralurk, Ghazbaran, Morgaroth) 
• Ruthless Seven: Made up by 7 Elite Demons (Apocalypse, Ashfalor, Bazir, Infernatil, Pumin, Tafariel, Verminor)
• Shiron'fal:It was initially created by dwarves, elves, minotaurs and other ancient races. Today it's made up of many more races, including humans.
• Circle of the Black Sphinx: Necromancers, Warlocks, Renegade Knights, Lady Tenebris (she later betrayed them and switched sides), and some creatures from Issavi and Oramond.
• Humble Path: Monks.
• Crunor's caress: Corrupted Druids.
• Shaig'laar: Probably elves.
• Planegazers: Humans.
• Knightly Orders (Cobra/Falcon/Lion): Scarlett, Oberon, Kesar respectively. 

There are probably more or less important and maybe I forgot some. 

If I remember or someone comments I can add them.

Sources: Books and NPC's from Tibia.

Comments

Quaras seems to follow a god too, yet im unsure if those on calassa are cultist of the same god that those on oramond, but both pirates on lb and oramond citizens can tell you about their cultist behaviour.

I will say they both are cultist of "the fire-feathered serpent god" or something like that.