Proposed Canon
Most Erfworlders believe in the Titans as Erf's creators or demiurges. Their divine will is used by Ansom, seeking to justify the traditional ruling systems of Erf, and by Stanley, who claims that the Titans have special plans for him that supersede the "mandate" of the royals, as evidenced by his attunement to the Arkenhammer. Images of the Titans are featured in the architecture of many cities; similarly, it would appear that some of the books popped along with cities make mention of the Titans.Erf-b1-p068
Some Erfworlders believe in an a City of Heroes, afterlife in which heroic deeds in combat are especially rewarded. King Slately also mentions the Hall of the Mountain King as a place of judgment after croaking, though the context of the comment suggests that this separate Titanic judgment is the purview of rulers and possibly only royal rulers.LIAB Text 9
While no other deities have been mentioned, the Woodsy Elf warlord Tarfu invokes the blessings or guidance of "wood spirits" over troops before sending them into battle.Erf-b1-p057 This would suggest some animistic traits in the beliefs of this Elf brand.
Vinny also notes in First Intermission 37 that Signamancers subscribe to an esoteric philosophy which holds that all Stuff is Foolamancy, or, in Real World terms, that the physical world is an illusion, simply a set of Signs that represent an objects true nature.First Intermission 37 It is not clear whether this is truly a religious belief, a belief attached to the Signamancer's magical discipline, or simply a philosophical point of view.
It should be noted that, at present, there have been no unit types introduced in Erfworld that serve a primarily religious or priestly function, although the men in book 2 page 12 look like monks. Casters appear to be the closest thing Erfworld has to a philosophical or priestly class, as they are most in tune with magic and spend much of their energy researching the arcane, as illustrated in Vinny's comments about Signamancers and Grand Abbie Janis's discussions with Sizemore throughout Book 1. However, while Casters have the free time and scholarly temperament to act as a priestly class, their subservient status to their Rulers makes it difficult to imagine how an organized religion could exist separate from a Sides power structure. So it is that, for much of the world, it appears that Rulers, and not individual units or organizations, set the religious policy and belief in their Sides. Thus, it is also the case that units with free-will like Rulers, Ruler-like units such as the leaders of Natural Sides and Barbarians, and to a lesser extent Warlords (which have some freewill, though it is tempered by their Loyalty to their Ruler and Side) are the ones that also debate the most about religious or philosophical issues.
An exception to this Ruler-specific religious bias appears to be the Magic Kingdom, where casters seem to have much more freedom. Sizemore notes in his discussion with Maggie and Parson that the residents of the Magic Kingdom "have endless arguments about things like that. Philosophy. Metaphysics. Nature."First Intermission 28 It has also been established that the Magic Kingdom plays host to an array of "barbarian," or unaffiliated, casters that are not bound to a particular side, as was the case with the casters of Unaroyal after the end of their Side.First Intermission 43 These unaffiliated casters, like Janis, serve as mentors for both affiliated and unaffiliated casters that visit the Magic Kingdom. They are also, therefore, the most capable of creating original religious and philosophical theories and organizing those theories into a coherent belief system amongst their fellow casters. However, the problem of free will appears again in this scenario, as there is no way for these belief systems to disseminate out from the Magic Kingdom unless they are adopted by other units with free will, like Warlords and Rulers.
 Religious War: The Battle for Erfworld's Spirit
While war seems to be a constant in Erfworld, the Great Western Conflict between Stanley the Tool and the Royalist factions aligned with Jetstone is increasingly ideological and fueled by religious differences regarding the mandate to rule. Both factions believe that the Titans have given certain individuals a mandate to rule, however each sect feels that their leaders are the "chosen" of the Titans. Roughly, these sects are:
- Toolism -- the belief that those that have attuned with an Arkentool are destined to rule. This belief system is championed by two of the attuned, Stanley the Tool and Wanda Firebaugh, and Ansom, whose decryption was the direct result of Wanda's attunement to the Arkenpliers.
- Royalism -- the belief that those of royal lineage, by the very fact that they are noble, are chosen by the Titans to rule. This belief system is the basis upon which most kings and queens in Erfworld justify their rule, and, in the Great Western Conflict, is championed by the rulers of Jetstone and Unaroyal, and the members of the Royal Crown Coalition.
There are also sides and individuals that could be considered agnostic in the schism. Charlescomm, which was employed by the Royal Crown Coalition prior to the reawakening of the volcano at Gobwin Knob, is ruled by Charlie, another of the attuned. However, Charlie has expressed a certain discomfort with the idea that simple attunement indicates that one is doing the will of the Titans.First Intermission 48 Similarly, up until the destruction of Unaroyal, Transylvito was relatively lax in its interpretation of Royalism, allowing lower-nobility like Caesar Borgata have commanding roles. However, since the death of Queen Bea, Don King has shifted his beliefs, and the direction of his kingdom, heavily toward the Royalist camp.
The popular consensus in the Magic Kingdom seems to be becoming increasingly hostile towards Gobwin Knob and Toolism. This is, perhaps, a natural reaction for these barbarian casters, both because a single, erfworld-wide side would have little need for their services and because, given the religious zeal with which it pursues its world domination, Gobwin Knob could, eventually, pose a threat to the Magic Kingdom itself. The sole exception to this growing animosity may be the Florists. However, it seems likely that this stance has more to do with their belief in Parson as a bringer of peace through war than in a belief in Toolism itself.
Lastly, of course, there is Jillian, now Queen of Faq, who in the past denied that royalty was important and led the life of a barbarian warlord. Jillian probably lacked the financial resources needed to rebuild Faq until she meet Don King, but her experiences as a Barbarian does give her a perspective quite different from that of the average Royal. Her willingness to ally with Charlie demonstrates her ability to think outside of the Royalist paradigm. If the traditional Faqian interest in philosophy reappears in Jillian's Faq, then a new religious philosophy combining elements of both Royalism and Toolism, or a different ideology entirely, may develop there.
A unit's religious beliefs are present when it is popped, though it may become more or less faithful depending on its experience.
Religious debates in Erfworld seem to take the form of the specific "plans" the Titans may have had for Erf and themselves: in other words, Fate. Indeed, talking about fate and destiny is likened to quoting scripture.