Religion in Tomos is based on veneration of the primary spirits of the four elements; each has an associated God and Devil. These beings send emissaries -- angeloi or daemon, as the case may be -- to intervene occasionally in events on Terra. These emissaries are powerful and apparently free-willed elementals at least to the extent that emissaries of gods are free-willed. Natural disasters can accompany their displeasure, while blessings of fertile fields and good weather accompany dutiful observances. The Devils deal with matters of darkness and harsh judgment, but may not necessarily be themselves evil; on the other hand, the distinction is moot to the sorceror who just got a critical failure and is being attacked by a fire daemon.
Temples to the Four Gods are separate in major cities but combined in smaller towns, with separate shrines. Central temples are situated on the Mountain of the Four Elements, a volcano at the center of Tomos' central mountain range with a lake and hot springs overlooking a steep cliff. The powers of Earth, Fire, Air, and Water are all on vivid display here, and priestly orders have their headquarters here.
Tomosics largely pay devotions in the form of offerings and sacrifices on national holidays, or before starting a major project. Most find Amalkur of Earth to be the God directly involved with their lives, and orichalcum is considered his blessing. Sailors, farmers praying for rain (or a rain mage), and the like make Lyn of Water a strong second-place finisher. Whess of Air and Zikti of Fire receive more cursory observances from most, though blacksmiths and alchemists pay their dues to Zikti.
Among the Four Devils there is little if any actual worship. Gur, the Devil of Earth, oversees important matters of necromancy, and his afterlife, Hellstone, is known to imprison certain living entities that cannot be killed and threatened Mankind in the past. Judges and necromancers give him some quiet respect. Durn of Water, Kass of Air and Kheiaou (that's "khay-ow") of Fire are shunned, though if a powerful daemon emissary of one addresses itself to you out of the blue, politeness is probably called for. Fortunately in the opinion of most Tomosics, it doesn't happen much.
The Varen Empire, of course, is monotheistically theocratic. The Four Gods are given due respect and sacrifice, since they obviously exist, and their emissaries occasionally bring pronouncements to Varens, but the One God of Singularity is placed above them as the binding force of the Church and the Empire. Among the Four, in their cold lands, Zikti is definitely the favorite. This is probably a carryover from previous worship before the Church was founded.
Oddly enough, the Four Gods don't seem to mind a monotheistic faith, and getting an emissary to comment on the matter straight is like trying to catch a wind.
The afterlives are physically-reachable places, one in each of the four major elemental planes, with a heaven and hell each devoted to rewarding or punishment various major life choices. The dead are nearly unrecognizable without a guide, and the Gods themselves are busy entities. Reincarnation is a known fact. Varens, however, believe that the cycle of reincarnation is a temporary measure intended to purify one for a final ascent into a higher afterlife.
The Sanguine conflate obedience to leaders with obedience to morality and the Gods; a typical citizen of the Alliance utters small prayers and devotions on a daily basis in the course of his activities, and the administrative classes are regarded with veneration near holiness.
The Mikraigai assign not only the elements but individualized portions of the elements to spirits, resulting in a religion something like animism, with the Gods simply being at the top of the deity chain.
The Azarin differ too much from nation to nation to pin down. Some consider one of the Four Gods as ascendant over the others; some consider it rude to even mention them except in carefully-prepared ceremonies; some even worship a Supreme Being, and find Varen beliefs a flavor of their own.
A recent development on Terra is the discovery of "unattached" elementals: these appear to be elementals in all respects, save that, like emissary elementals, they are not subject to Control spells. They have no memory of a prior existence, and find themselves at a loss to explain how they came to be. Some of them enter into the fringes of human culture, experiencing existence and trying to find a place in the world. All but Fire elementals, modified by a later template, are suitable for use as characters.
Theories abound on what these elementals are. Has Void magic uprooted an emissary from his lord? Has the spread of humanity torn a natural elemental from its roots? No one is quite sure what is going on, even the elementals themselves.