Gefendur is the overwhelmingly dominant faith of the Kasslynian continent. By most estimations this ancient religion is as old as civilisation itself, and has exerted its influence throughout the millenia on everything from the Kasslynian calendar to naming conventions to international boundaries.
Most historians agree the faith began in the southeast among Kasslyne's earliest hunter/gatherer tribes, likely in what is now southern Sharteshane. Through warfare and conquest the influence of these savage tribes spread west, obliterating competing beliefs. Even today the Gefendur religion is a greedy faith, proselytizing by the sword and relishing the destruction of those who do not submit to its four gods. Having decimated all other belief systems long ago, Gefendur now stands supreme and largely unchallenged throughout most of Kasslyne, bowing only to Ssaelism in Alderode.
The Gefendur believe in a pantheon of four gods: the elder twin siblings Riv and Yerta, and their younger twin siblings Baelar and Tirna. These four beings exist outside of time and outside of the world, which remains in perpetual incubation in Yerta's womb. Wishing to propagate themselves, the gods created humankind as their own children, but will not accept them until they individually can prove their worth. Hence the proving ground of the terrestrial world, and the cycle of birth and death and rebirth, which all humans must endure until they emerge whole and godlike and perfected before Riv's judgment.
In creating the world, the Twins wove their wisdom into a vast network of Laws and Ideals called the khert, draping reality atop it like skin stretched over a skeletal frame. To most Gefendur, the khert is in itself a deific entity, as it determines not only the nature of reality but the place of humans within it upon their repeated births.
Apart from the four gods and the khert, Gefendur also worship a host of Victori (vaosa, in Tainish), once mortal beings who achieved perfection and exist now just below the level of the Twins. These Victori often act like lesser local deities and fabled heroes, and are sacrificed to by supplicating Gefendur who feel their problems not worth the attention of one of the Twins. Victori worship can be cause for concern by the Gefendur Church when it is taken to extremes, and imprisonment and even execution can happen if a person is suspected of forsaking the Twins in favour of a Victori deity.
Gefendur Scripture consists of an ancient codex of didactic myths and legends that stress charity, justice, humility, piety, and filial responsibility. It stresses Gefendur faithfulness above all else, rewarding the martyr and damning the betrayer. By serving the Twins, following their laws, spending their final life in the Gefendur priesthood to learn about and more fully experience the perfection of Creation, and navigating the perils of Outside upon their death, a faithful Gefendur can perfect himself and finally achieve the Twins' vast kingdom.
To the Ssaelit, three of the Gefendur's primary practices are most abhorred. The first one is their belief that all dead must be interred in the earth, returning them to the soil which is Yerta's flesh. To disturb a corpse once they are interred is a serious sin, but corpses outside of burial are no one's property, and thus the idea of using them as recycled labour is not troubling.
The second practice of the Gefendur is the life of their priests and priestesses. Gefendur clergy live apart from laymen in large cloisters, are restricted from marriage or relationships, and produce prophesy via copious ingestion of the softi plant, which induces visions. Gefendur clergy form large groups once a month and travel their district, preaching, doing charity work, and gathering food and money from the faithful.
The third Gefendur practice is the most despised of the Ssaelit: Cannibalism. Twin children are bought from their parents at birth by the Gefendur church and raised in cloisters. The twins are brought up with the pious ideals of Gefendur scripture, and lead lives apart from the outside world. At no younger than twenty years of age, the youngest of the Twins is poisoned with softi and its flesh carved and roasted and eaten by Gefendur clergy, local state officials, and anyone who can offer a large enough sum of money to the local diocese. To eat this softi-blessed flesh ensures great fortune and prosperity, and all but promises Yerta's favour upon one's death. This strange feast occurs biannually, at the beginning of Yerta's quarter (The Mother's Day or the first day of Spring) of the year and Tirna's quarter of the year (The Sister's Day or the first day of Autumn). The Gefendur calendar revolves around these two events.
Yerta the Eldest Sister
Yerta is the mother goddess, the bearer of the world who nurtures and protects. By Sororal Gefendur she is recognized as the wisest and most benevolent of the four. In most stories from Scripture, her manner is harsh but she always acts in the best interest of her terrestrial children. It is usually accepted that Yerta exists outside of time although in some stories she is said to have a pet fawn so fleet of foot that it has traveled to the end of time and back and it whispers the future in her ear.
Yerta is associated with childbirth, child rearing, the earth, plant life, wild animals, and death. Though her image can vary wildly from country to country, she is almost always depicted as fat and round with pregnancy, and with cloud-mottled sky-blue flesh.
Tirna the Youngest Sister
Tirna is the reckless goddess, the child, who is closer to mankind than any of the other gods. She is considered an "imperfect deity", an aberration, but still above the earth-crawling children in Yerta's womb. She is not evil, but imperfect, and is seen as a sort of bridge between the terrestrial and the celestial. Tirna was murderously displeased with the creation of mankind and tried to feed Yerta leaves from the softi plant to kill the life in her womb. The plot was foiled of course, and Yerta devoured her sister instead, banishing her to her belly and the mortal world within. Ever since, Tirna has longed to appease her siblings once again and turned her attentions to aiding mortals. It is believed she possesses mortal twin children, gifting them with foresight and prophesy. Banished eternally to the mortal world to pay for her mortal caprice of ill temper, Tirna is a tragic figure of a god and the Gefendur faithful find her far easier to relate to than the aloof Yerta and her brothers.
There is another take on the Youngest Sister however, one which claims she is not repentant for her crime so much as eternally enraged. It is this tradition that has for thousands of years encouraged a cult of human sacrifice in the Gefendur faith, one wherein half of a pair of twin siblings is poisoned, and their flesh eaten by Gefendur priests in order to appease Tirna's terrible temper.
Tirna is associated with mortal frailty, sickness, starvation, and natural catastrophe. Often she's depicted as a being split in two between callousness and compassion.
Riv the Eldest Brother
Riv is the "father" of the living world, as it was his seed that gave life to the arid earth in his sister's sacred womb. Traditionally depicted as an angry, tempestuous tyrant, he still bows unquestioningly to Yerta's commands. Riv has the demeanour of a blustering husband in the holy stories, and Yerta infallibly must shield the living world from his temper. He is, however, a beautiful singer. It's his song that awakens Yerta every morn, opening her eyes and bringing light to the world. Although it is the Eldest Sister that judges souls, Riv is their guide through the realms of the dead and he often decides their fate when there is hesitation from Yerta. For this reason, Riv is frequently exhorted by the families of the deceased who aren't quite certain how their loved one will fare in the afterlife.
Riv is associated with the sea, throbbing eternally against the female earth, and many ships carve his form into their prow and keep a shrine to the divine Father somewhere shipboard. Birds are sacred to him, as well as the creatures of the deep, especially the singing whales. Many sailors will have his symbol tattooed somewhere on their body. He's the avatar of virility, manhood, power, and all things macho.
Baelar the Youngest Brother
Baelar is the warrior poet, the perfect soldier, and the creator of pymary. In times of conflict he is worshipped almost exclusively. Other times, he is a symbol to wrights, both masters and aspirants, though soldiers will often ask a priest to bless their swords in Baelar's name. A careless, distracted sort of deity, Baelar is thought to influence the outcomes of battles arbitrarily, favouring those troops most willing to die one day, and the next giving his blessing to the cowards. All the same, soldiers (and anyone wishing to succeed in a difficult task) will sometimes wear an iron ring on a chain around their neck and over their heart - a traditional archer's target - in a facetious attempt to confuse the fickle god.
Baelar is associated with the heavens and all things intangible - pymary, literature, mathematics, and the sciences.
There are two major Gefendur sects. The dominant one by far is the Sororal sect, a Gefendur tradition that places Yerta and Tirna at the head of the pantheon and believes that the world was created through consensual tryst between Yerta and Riv. This tradition is state-enforced in Cresce and has a great effect on that country's social traditions and culture. In Alderode, however, the Fraternal sect dominates. In this tradition it is Riv that leads the Twin Gods, and Yerta is not pregnant with the world but rather glutted with it after feeding on the chaos of eternity.