Religion comprises the beliefs which are held in relation to the divine and the supernatural, and the social structures through which they are expressed. There exist a plurality of religions in the world, and of these the most sophisticated are the three which are characteristic of Messenic civilisation—Cairony, Siriash and subsequently Arlatur—and the Joriscian faith of Vaestism.
- Arlatur emerged from the studies of the Siur savant and philosopher Ragna Hrafnamaður in the early seventh century, largely as a reaction to Thúrun, but with some influence from Cairony. Arlatur denies the existence of an external divine entity in favour of an internal divine fragment, the neisti. The ultimate goal of all neistir is reunification with the all in einingu, and Arlatur teaches that living in ways that benefit and improve one's surroundings will allow the neisti to consciously experience that unity.
- Cairony started to form as the Six Holy Sisters preached for reform of the old Senuminist faith of the Sabāmani people in the 8th century BCE, which was continued under the auspices of the Glorious Prophetess at the beginning of the Cairan Era, propulsing the faith on the world's stage. Cairony teaches that the world as it exist today is the imperfect result of a cosmic war known as the Great Upheaval between the universe's architect, Aedif, and other powerful spiritual entities. Humans of today are to work in conjunction with Aedif and other spiritual beings to repair the universe into its originally perfect state by the permanent application of practices such as Cairon Engineering.
- Siriash developed as a reaction to the old Palthachist faith of the Dammurites and later Larhines, centred around what Sirians believe to be the mortal incarnation of Nevaras, a demigod-like being, who was cast down from the plane of Archtum for attempting to teach the secret of Ascension to others and banished to the plane of mortals. Nevaras sought to teach humanity how to achieve spiritual enlightenment in order to ascend to a higher plane of existence, where he is believed to be massing a celestial army to bring down the false gods that are said to feed off the spiritual corruption of mortals.
- Vaestism is founded on the teachings of the Prophet, whose work bridged the 14th and 15th centuries. Developing from its emergence as a Cairo-Sirian heresy, Vaestism teaches that the world is balanced between the infinite realms of Light and Dark, and that it is incumbent upon humans to gain and regiment Knowledge so that they might transcend this cosmic struggle through their regulated will. Vaestic teaching accepts the idea of reincarnation, but holds that it is arbitrary and unpredictable, and in bleak contrast to Sirian orthodoxy, it puts forward the view that humans are bound to reincarnate as humans if they fail in transcendence.
- Bhramavada is the global term for a group of overlapping systems of belief broadly centred on the concept of a mahanasatya or "universal truth", of which the physical world inhabited by human beings is considered to be a vague reflection. Thought to have originated in what is now northern Adorac, it has expanded to become prevalent across the greater part of Ascesia, though conversion efforts by Messenians and Vesnites have weakened its hold significantly.
- Pyranism is a polytheistic faith which originally developed in the central western regions of Lestria; it holds that the physical world was made by the creator-god Abban as a testing ground for human spirits, which return to Abban to be assessed as to their fitness to enter the greater and truer world which lies beyond. While most strongly associated with the Baygil Empire, its present reach extends along the entire western coast of Lestria and also into south-eastern Ascesia.
- Ishtinism was a widespread religion in south-eastern Outer Joriscia, unusual for its belief in the existence of a single god, Ishtin. After the collapse of the Chotarian Empire, Ishtinism retreated before finally being extinguished by the rise of Vaestism. Certain Ishtinist rituals were carried over into Vaestic practice.
- Palthachism was the religion of the Dammurites of southern Messenia, a polytheistic system of belief in its earliest form. Weakened by natural disaster and social change in the region, it was radically reinterpreted in the form of early Siriash; the new faith rapidly drove its parent to near-extinction by the middle fifth century BCE, and it survives today only as small scattered fringe cults.
- Thúrun was the indigenous faith of much of far western Messenia, a polytheism that grew out of animist practices in the region. Influenced in part by Palthachism emerging from the south-east, it dominated and largely sidelined the newcomer, but was itself gradually displaced as Arlatur spread among former Thúrun adherents.