predominant faiths of the City and its continent, Tom, chronicler of Middenmurk, asked about the role of clerics in the world--a topic I’ll take up today.
Many Oecumenical priests and monks, and Old Time Religion preachers and evangelists, have no magical powers whatsoever. The Good Book cautions against sorcery and witchcraft, and at various times and places throughout history its adherents have persecuted magical practitioners. Given the demonstrable reality of magic, and its obvious utility, this prohibition has had about as much success as the condemnation of prostitution or sexual promiscuity by religions of the world we know.
In fact, folk have continued to practice apotropaic magic to ward off evil through history. Even churches have been built with such workings placed on them. Folk-grimoires of Good Book-inspired magic have been used by rural magical practitioners and wise-folk for centuries. This has only sporadically been seen as “sorcery”, and seldom persecuted. The spells and rituals found in these grimoires are of protection for human or livestock from harmful magics or other sorts or harm, magical aide for everyday activities (agriculture, cooking, etc.), or the provision of luck. Many pious followers of the Old Time Religion, particularly in rural areas, are practitioners of this type of magic to this day.
The more centralized Oecumenical Hierarchate discourages this folk use (with only the mildest success) but has established certain religious orders whose goal has been the acquisition and mastery of magic for the greater glory of the Church and God. They tend to prefer the term theurgy ("divine-working"), and disparage the godless (and potentially soul-imperilling) thaumaturgy ("wonder-working"). These orders (both priestly and monastic) wield magics as powerful as any thaumaturgist, though their spells and rituals are somewhat different, having arisen by parallel development.
Despite the philosophical differences between these religious magic-users and their more secular rivals, there is no real functional difference between their two styles of magical practice.
There is a third type of religious magic-wielder who is fundamentally different. There are many names for such individuals but they're often called “gifted” or “miracle-workers.” Some thaumatological scholars have suggested that these individuals are actually mystics of some sort, but the gifted themselves believe their powers are granted by their Deity, or by their faith in the same.
Gifted manifest powers like speaking in tongues, healing, turning/destruction of undead, protection from evil, or supernatural strength or vitality. Some gifted have even been said to be able to appear in multiple places at once, or to fly. The gifted only have these powers when they are acting in congruence with the dictates of their god, or, as some scholars have pointed out, when the gifted person believes himself to be acting in accordance with his god’s will. These abilities tend to be activated by prayer, or song, or in some cases more extreme acts like self-flagellation, or ingestion of poison--any religious ritual to focus the mind and the spirit. These are idiosyncratic, varying from person to person.
Interestingly, the phenomena of those with gifts of faith is more common in rural areas than in urban ones, and more common among followers of more ecstatic sects than mainstream ones. It’s also in no way confined to those who actually have religious ordination or authority.
So those are the “faith-based” magical types of the City and its world. Exact game mechanics are yet to be determined (and open to suggestions), but I hope this provides the general idea.