Perhaps the oldest institution on Arvum, the Faith of the Pantheon has existed long before the Reckoning, and is believed to have originated out of Sanctum, the seat of House Valardin. Even today, the Faith is still dominated by most of the western houses, though officially the Faith bears no allegience to any house, and all who wear the formal robes of priests and priestesses of the Faith must become godsworn and set aside their families, vow to only serve the gods and the crown, and abstain from marriage or gaining or granting inheritance.
The hierarchy of the Faith is as follows:
The Most Holy: The Dominus of the Faith, Voice of the Pantheon and Closest To the Gods, the living embodiment of the Faith in the world. The Dominus serves for life, and acts as Seraph of Arx, with all members of the Faith ultimately answering to him (or her, in the case of a Domina). When the Dominus should die, the three legates gather in the Star Chamber of the Rectory and start the secretive process of choosing the next Dominus, involving each Archlector in turn judging the nominee's recitation of a god's tale in regards to their patron deity while overseen by the three legates. The last Archlector called is always that of the Thirteenth, who then acts as Tehom's advocate and argues the case against the nominee and why they may be ill suited.
Fathers and Mothers of the Faith: The Three Legates. The Legate of Concepts, also know as the Legate of the Shield or the Shield of the Faith, oversees the devotees of Gild, Limerance and the Sentinel, and the associated Archlectors and the Grandmaster of the Order of the Knights of Solace. The Legate of Arts, also known as the Legate of the Sword or the Sword of the Faith, oversees the devotees of Gloria, Jayus and Vellichor, with the associated Archlectors (including the Archscholar of Vellichor) and Grandmaster of the Holy Knights of the Templars. The Legate of Creation, known as the Ward of the Faith, oversees the devotees of Petrichor, Mangata and Lagoma, though they are traditionally tasked with the appointment of seraphs to parishes and have enormous sway over how tithes are collected for the Faith.
The Blessed: The Archlectors of each of the gods of the Pantheon. In theory this is a position tasked primarily with theological work and the development of worship of a specific god, but in practice most of the positions are concerned with bringing the rural discipleships that veer away from the Faith back under the auspices of the Faiths' control. Some, such as Archlector of the Sentinel, have essentially lost control of their discipleship (such as when the Inquisition, originally a faction of the Faith dedicated to the worship of the Sentinel, became a secular investigative body for the crown), while the Archscholar of Vellichor controls an entire institution in his own right. All report to their legate, save the Archlector of the Thirteenth, whom reports to the Dominus. The Grandmasters of the Templars and Knights of Solace respectively are treated as peers of the Archlectors and report to the legates or the Dominus.
Brothers and Sisters of the Faith: All godsworn typically are referred to as brothers or sisters, recognizing that they have left their families behind and now only have a family in the Faith. This includes any who have formally become priests of the Pantheon (which the majority of laity in the discipleships never do), as well as templars and knights of solace who have taken their vows. Seraphs are priests who are appointed as heads of individual parishes, which can be as minor as a seraph of a tiny village, or the Seraph of Sanctum, the seat of House Valardin and original home of the Faith- a prestige posting that is often seen as a sign that the seraph is likely to become an archlector, legate, or even the Dominus.
Children of the Faith: Any laity can join the discipleships to the different gods, which vary from institutions with a great deal of organizational control (the Scholars of Vellichor, for example) to completely informal arrangements with no oversight by the Faith whatsoever (the Drinking Discipleship of Mangata). The Templars and Knights of Solace have a great number of men-at-arms who never formally take godsworn vows and become knights, but fill their ranks and provide the Faith with military might to rival the great houses, even if it's scattered throughout the entire Compact of Arvum. While the godsworn might refer to a disciple as 'child', it is not uncommon for laity to address any disciple as a brother or sister of the Faith, even though formally they have not been inducted into the Faith of the Pantheon by taking godsworn vows.