How strangely high endeavours may be blest,
Where piety and valour jointly go.
John Dryden
Piety is holy energy that the gods share with their priests so that the priests may perform miracles. The gods grant piety to the priests who most please them. There are two ways to please the gods: through devotional prayer, and by gathering followers for the god.
In devotional prayer, the priest removes himself to a holy place and spends a week contemplating the nature of holiness, praising his deity, and performing holy rituals. His god rewards this activity by granting him 2 additional piety. To perform devotional prayer, a priest should be in one of his god’s temples, and use the “Devotional Prayer” prayer.
When a noble first becomes a priest, his god will reward him with enough piety to dedicate a temple (so that he can perform Devotional Prayer).
The gods are also pleased by priests who recruit new worshippers. Each month, the gods grant their priests piety based on how many followers each priest has. Followers are non-priest (and non-mage) nobles who have dedicated themselves to a priest (see Followers).
For each religion, each month the priest with the most followers receives the designation of “High Priest” and 12 piety. He also receives 10 angels (see ‘Monster combat ratings’) from his god. These angels will be in the High Priest’s control until the end of the month, when they are recalled to the spiritual realm.
The two priests with the next most numerous followers receive the designation of “Bishop” and 6 piety. They also receive 5 angels each.
For religious skills which require a priest to be alone, angels and golems are not counted. That is, a priest with 10 angels is still considered to be "alone".
Of the remaining priests, the half with the most followers receives 3 piety each. The other half receives no piety.
(The actual levels of 12, 6 and 3 piety may change from game to game. Check the individual game set-up to confirm the levels.)
The gods also limit how much of the god’s power a priest can "stockpile". Typically, a high priest is allowed to collect piety up to 5 times his number of followers. All other priests may collect piety up to 3 times their number of followers. Again, these limits may be varied in the game setup.