One of the things I cling to is the list of the initial disciples of the Prophet. While there is no shortage of possible heresies and convoluted catechisms that can no doubt be created, there are some important core elements that should be reviewed to retain the flavor.
On page 18 of the 2nd Edition revised rulebook, there's a boxed portion titled "The Virtuous Disciples". I use this list of virtues and saints a lot when crafting stories and teachings from the religion's holy texts:
- Paulus the Traveler (Questing) - also the patron saint of charioteers (space pilots and navigators), Paulus embodies a virtue that is one of the major themes of the game. Questing refers to the constant search for truth and the perfection of the mirror of the soul so that it might properly reflect the Holy Light of the Pancreator. It also gives an impetus to go out on adventures, rather than just sit at home and navel-gaze.
- Lextius the Knight (Loyalty) - as a knight, Lextius would probably be upheld by many a faction trying to instill fanatic loyalty in its members, in much the same way the beatitude "blessed are the poor in spirit" was shortened to "blessed are the poor" when taught to the less fortunate countries and members of society. Still, it would be important in a setting where the fabric of society is upheld by powerful factions carefully balanced against one another. I'd imagine his image would be very prevalent in training grounds and initiations.
- Amalthea the Healer (Compassion) - healers are told to be compassionate, and that allows us to partially avoid the problem found in some D&D games where clerics refuse to aid other PCs unless they've converted to the patron deity. Furthermore, it serves as a valid motivation to bypass one of the "sins" noted by the Church: Invention.
- Mantius the Soldier (Protection) - certainly, any adventurers would seek Mantius's intervention when embarking on dangerous missions. Others might view it as a calling, however, and hear the call to becoming bodyguards and vigilantes as part exercising the virtue of protection.
- Maya the Scorned Woman (Justice/Retribution) - speaking of vigilantes, Maya would certainly be another saint that would garner attention when seeking to right a wrong. It would not be difficult to envision this defiant chained woman's image adorning doorways of the reeves and halls of justice of the Known Worlds -- perhaps even in their jails and places of punishment.
- Horace the Learned Man (Wisdom) - the books portray Horace as highly intelligent, and one capable of a battle of words against the Prophet Zebulon before he was converted. His conversion serves to highlight the difference between intelligence and wisdom (which many D&D veterans already understand) and makes it likely that the Known Worlds culture would been keenly aware of the difference as well.
- Hombor the Beggar (Humility) - humility is a hard thing to endure in a rigidly structured society. When people don't have much, they take pride in things that they do have -- being a servant, for example, may be valued as a respected place in society (as portrayed in the TV series Downton Abbey and the movie Gosford Park) despite the fact that they're not really recognized by their "betters". And they may take great offense if that place in society is belittled. Furthermore, silence would probably be under the bailiwick of this virtue, along with self-deprecating humor -- making it appropriate for this sly saint to represent this virtue.
- Ven Lohji the Ur-Obun (Discipline) - an alien disciple of the Prophet, one that comes from a culture with its own ancient religion, makes for an interesting saint. That he represents discipline is probably a nod to the belief that aliens cannot truly understand human values and cannot enjoy true salvation -- but can follow the rites and rituals and enjoy the sacraments and therefore enjoy some measure of benefice in this life.