From Post-Lament Anthropocene: Comprehensive Mirror for Historians - Rinascita :
The Order of the Deep worships Sentinel Imperator. The Order's clergy serve as the Sentinel's earthly emissaries, ensuring the people remain faithful to Their divine will.
In Rinascita, the Sentinel's Resonator is revered as the "Enlightened one". The Order's leader is known as the Primus, and its current Primus, Fenrico, has declared himself to be the "Enlightened One."
Beneath the Primus, Priests oversee the rites and sacred duties of the Order, while the Acolytes dedicate their lives to the study of the Codex and spreading the Sentinel's teachings throughout Ragunna.
From in-game description:
The Order of the Deep worships Sentinel Imperator. In Ragunna tradition, the Order's clergy serve as the Sentinel's earthly envoys, entrusted with guiding the people in Their divine word.
The Order is led by the Primus, and the current Primus, Fenrico, has declared himself the "Enlightened One," the Resonator of the Sentinel. After the last Carnevale, he proclaimed to have discovered the way to commune directly with the Sentinel.
Beneath the Primus, the Priests oversee the rites and sacred duties of the Order, while the common clergy, known as Acolytes, spend their days poring over the Codex, spreading the Sentinel's teachings throughout Ragunna.
To uphold divine order, the Order commands three distinct branches:
Order Tribunal: The Order's secular judicial body that handles civil and criminal matters between families and commoners.
Chamber of Discipline: The Order's executive arm that commands the military to enforce the law. The Chamber heavily employs Echoes in combat, and its enforcers are often called "Inquisitors."
Order Penitentiary: The Order's religious court that trials heretics and faithless who question and defy the divine teachings of the Sentinel.
The Order of the Deep serves as the de facto governors of Ragunna, overseeing city policies, diplomatic relations, and civil disputes—both large and small—are uniformly managed by the Order.
The Order worships sentinel Imperator, and is recognised as the "Humanity's Guide"
At some point in the past, the Sentinel ceased communicating with the Ragunessi. It is said that the only individual capable of directly connecting with the Sentinel now is the Order's current Primus.
In recent years, Primus has issued a series of decrees restricting artistic themes, which have sparked mixed reactions among the populace.