|This article is about an older version of DF.|
A deity is the object of worship chosen by a creature. Deities are randomly generated during worldgen, and assigned different spheres (the objects, creatures, concepts, etc. they are associated with).
Worship and deities differ among races: Dwarves and Humans worship multiple deities, most of which are often depicted as their own race, though on occasion they may worship a deity that is depicted as an animal or vermin. Elves do not worship a deity, but believe in a single force that permeates the forests.
Each dwarf and many other creatures have one or more deities listed among their relationships. In the case of your dwarves, you can see the degree of belief they profess ("faithful worshipper", "casual worshipper", etc.). Fortress mode does not currently include priests or temples, but does include representations of dwarven deities in statues, engravings or figurines (which were described in older versions of the game as "idols").
In Adventurer mode, Human and Goblin towns include temples inhabited by Priests that may be dedicated to a deity. If the conversation option "Service" is used with any Priest, the deity will be added as an object of worship to the character's record, and it becomes possible to speak to the deity from any location, though the deity will not respond.