Religion takes a few different forms in The World.
The worship of the gods is usually referred to in scholarly circles as “received theology”. (Common practitioners usually don’t see a need to name it anything in particular.) Received theology is by far the most widely practiced religion because the existence of the gods is very difficult to deny. There is much evidence, empirical, historical and anecdotal, that the gods not only exist, but occasionally get involved in the Material Plane; gods like Valestnaya and Prangdon are often seen at battlefields even today, and there are a lot of accepted and reliable accounts of divine intervention throughout the Second and Third Ages. Received theology is also not a very organized religion; it’s practitioners are united only in their acknowledgment of the gods, but the way the gods are worshiped (if in fact they are) varies from god to god and person to person. While most everyone recognizes that the gods are real, most honor a select few, and an individual may only choose to serve one. Additionally, most of the gods are fairly aloof, interacting with mortals in subtle and indirect ways, if at all, so even among worshipers of the same god there tends to be a lot of disagreement about the proper way to worship that god.
Despite it’s lack of organization, received theology has the most consistent and well enforced canon of any religion. The reason for this is because the study and practice of religion so often interacts with the study of history, which falls under the purview of The Consortium for the Preservation of History, which is notorious for quieting dissenters. The Consortium isn’t very concerned with the nature, character, or machinations of the gods per se, but anyone who denies the appearance of The Lovers at the Great Wedding, for example, is running against historical canon and faces censorship.
Non-clerical scholars of received theology tend to categorize the gods into Major Deities, who are generally gods and goddesses who oversee races, and Minor Deities, who have larger areas of interest. (Clerics, on the other hand, usually see whichever deity they serve as the major one and the rest as pretty minor. Most of the gods themselves seem to have a similar view, and those who don’t are usually unconcerned with such petty distinctions.)
Bahamut – God of good dragons
Corellon Larethian – God of elves
Garl Glittergold – God of gnomes
Gruumsh – God of orcs
Kurtulmak – God of kobolds
Lolth – Goddess of drow
Moradin – God of dwarves
Tiamat – Goddess of evil dragons
Yondalla – Goddess of halflings
The Lovers – Dieties of love
Bokonon – God of lies
Valestnaya – Goddess of death
Prangdon – God of strategy
Tadellor – God of the Hunt
Lililam – Goddess of Necromancy
Tayoress – Goddess of Magic
Elnet – Goddess of Medicine
Aquiler = God of Fertility
Ajenam – God of the Sea
Sinetan – God of the Sun
Demorid – God of Pestilence
Ladellal – Goddess of Nature
Silim – Goddess of Swarms
Marondan – God of Storms
Lachedic – God of Assassinations
Nayorel – God of Conquest
Berondan – Goddess of Espionage
Elturea – Goddess of War
Some settlements have more organized religious practices than the general Received Theology. These organized religions are usually centered around a Domain, and practitioners hold all deities of that domain in equal importance. Most notably, the official religion of Dumnezeustad is based on the worship of Light deities, and consider the worship of Death deities to be heresy.
The Old Faith
The Old Faith is the name commonly given to the worship of nature itself. Practicioners of The Old Faith usually give respect to the gods, but aren’t very concerned with them. Most Druids practice The Old Faith (though many worship Ladellel).
There are a few small religious groups that have religious views far outside of the mainstream. While these groups are small in number, they are surprisingly wide spread, and can be found all over The World, spreading surreptitiously through word of mouth, and conducting their business through underground networks of priests, clerics, and other operatives. These cults are considered heretical by most people, and in many places membership in a cult faces strict legal penalties, often including execution. Among the more notable cults are:
The Church of The Great Mother
The Church of The Great Mother is a monotheistic cult; they believe that there is but one deity, who they call The Great Mother, and that all other gods are a lie. They claim that originally The Great Mother inhabited The World, and that all peoples showed worshiped her, but an ancient battle in The First Age led her to flee to some other plain, and it was her absence that caused mortals to begin worshiping false gods. They believe that she embodies all domains, and that all divine casters call on her power whether they realize it or not. They dream of a day when all conflict will be eradicated from Morrendesil and then The Great Mother will return.
The Planeswalkers don’t believe that any deities exist at all, and that the domains and divine spells come from the planes of the multiverse. Most Planeswalkers are on a pilgrimage to travel to as many planes as they can, and to gain what knowledge and power they are able to. They see the Material Plane as a kind of prison for the unenlightened. Many Planeswalkers are actually arcane casters (warlocks in particular), and the few who are divine casters are usually druids who tend to view “nature” in a more inter-planar sense than most.