The gods who are known to Cerilia were present as heroes at the Battle of Deismaar which was the climax to the War of the Shadow. Events at this battle created The New Gods and the Abominations. The gods who emerged from the battle include

• Haelyn
  
• Erik
  
• Nesirie
  
• Ruornil
  
• Sera
  
• Avani
  
• Kriesha
  
• Belinik
  

Later other gods emerged which were understood to be offspring of the post-Deismaar pantheon. These include

• Cuiraécen
  
• Eloéle
  
• Laerme
  

Still other gods, typically non-human gods, are also thought to exist. These include

• Moradin
  
• Kartathok
  

A dark power is said to be at work in the Shadow World. The nature of this entity is unclear.

• The Cold Rider
  

Several of Cerilia's non-human races have sought patronage from powers deemed by some to be something other than gods. These include:

• Torazan
  
• Yeenoghu
  
• Baphomet
  
• Kostchtchie
  

Other entities may or may not exist. This would include other divinities which are always grouped with a god included above, such as the dwarven pantheon which may exist beyond Moradin, but has no distinct set of temples, worship, or political power which requires separate identification, except among dwarf specialists. Others may include deities which are not universally recognized. Still others, such as the Serpent are more commonly recognized among the Awnsheglien. Finally, those dwelling on other continents, such as Aduria may recognize other powers or deities.

The worship of the post-Deismaar pantheon is near universal among the humans of Cerilia. Worship is conducted primarily at temples under the guidance of clerics. Private worship and prayer are typical among the pious members of the faith. In the generations since the founding of the new faiths in worship of the post-Deismaar gods, the faiths have split into sects with differing doctrines, politics, and even differing alignments. Each sect will have its own dogma, calendar, centers of worship, affiliated orders, special activities for its clergy, symbols, vestments, and even mission.

Dividing the faiths into rival sects creates nice opportunities for conflict. Creating different doctrines, alliances, holidays, and alignments furthers division between the sects. The Birthright setting is full of opportunities to create conflict between kinds of people who might be friendly or even helpful in other settings. Particular to this example are clerics of the same god. The Impregnable Heart of Haelyn and the Orthodox Imperial Temple of Haelyn experience a schism both political and doctrinal. The Impregnable Heart is not only born of the independence of Roesone and Ilien from Diemed, but also rejects the emphasis on rites and ceremonies, a strict interpretation of the social order, and various readings of the Book of Laws.

Like every other type of holding, temple domains are ruled by one person. This person must be a scion in order to collect regency from the holdings. Typically this ruler is also the high priest of the temple, but sometimes the high priest is a lieutenant of the domain ruler. Below the high priest, are the key organizational heads of the temple. Typically they reside in the place where the principal site of worship is located. These people may be lieutenants, cohorts, friends, allies, rivals, leaders of affiliated orders, supervisors of temple functions, or even senior priests from individual provinces. Each temple selects these people differently, but they all exist. No ruler runs the temple domain alone, there are always underlings to help, hinder, or complicate their ruler's actions.
Whether they are part of the leadership team immediately below the ruler, or whether they are subordinate to that group, there is always a temple priest who is the leader of every province. In provinces where there are very small holdings, that leader may be the only member of the clergy who attends to a very small number of worshipers and the occasional supplicant. Large holdings may find a powerful provincial leader with many priests and even several smaller temples answering to him. The High Druid of the Oaken Grove of Erik is Günther Brandt, and he lives in Riveside in Dhoesone. The senior druid in Yvarre in Rjuvik supervises a level four holding and therefore has many subordinates himself. If the ruler of a temple domain is not careful, he might find that a Great Captain event occurs in his domain and one of his provincial leaders, or even a member of his inner circle attempts to break away and form a new sect.
Along with the vertical hierarchy that leads from the high priest of an entire domain down to the lowliest new acolyte, they may also be affiliated orders and other allied organizations. A temple domain of Ruornil, for example, might have an organization of wizards who serve the temple with their arcane power, while another organization, such as the Order of the Silver Crescent in Medoere might be composed of knights. Still another organization might be composed of rangers, scouts, and rogues, like Ruornil's Silver Guard in Grevesmühl to protect wild places and source manifestations. Still another organization might be composed of those who are dedicated to oppose the encroachment of the Shadow World.

The Advanced Dungeons & Dragons 2nd Edition sources mentioned a few organizations affiliated with temple domains, such as the ones actually named in the above example. Current editions make much greater use of organizations in general, and given the Birthright setting's emphasis on organizations in the second edition, its doubtless that organizations would be even more plentiful playing Birthright with a Dungeons & Dragons Edition 3.5 ruleset. Rules governing prestige classes, contacts, responsibilities and benefits of membership, and a whole chapter on affiliations in the Player?s Handbook II, all demonstrate how much the mechanics of organizations have flourished in the current edition. Its hard to imagine that organizations are not proliferating no matter what edition is being played by the ideas put out there with each new supplement.

Every deity has enemy faiths. These faiths and their sects and clerics are sure to meet unfriendly or actual hostile reactions. Worshipers are careful never to give reverence to gods hostile to their own patron. Among friendly gods, one might expect a friendly, or even helpful reaction, unless history, politics, or some doctrinal disagreement seperates them. After all, as mentioned above, even sects of the same god may be hostile. Reactions from clerics or sects which are indifferent to one another might run from a warm welcome to immediate hostility depending on circumstances. In general, you are much more likely to encounter an enemy than a friend. That's why you carry a sword.

There are three things that attract most people to a patron deity. Each nation has its own patron, and members of that cultural area are more likely to take solice and wisdom from the teachings or clerics of their nation's patron diety. Each diety also shows favor and protection to certain professions, and members of that profession are that much more likely to seek the protection of such a patron. Finally, characters will consider the alignment of a god when considering their patron.
Culture, class, and alignment will be the most common factors for a character when selecting their patron deity.

Many domains find common cause with another domain and ally for their mutual advantage. One of the most powerful alliances can form between a landed domain, or realm, and a religious domain. Such an alliance between the state and its one religion is often refered to as a state religion. One special example of a state religion is a theocracy. Of course in that case, there is no alliance between two domains, but a single ruler who unites both in a personal union.