Epithets in Ancient Greece
Divine epithets crop up in even the most shallow dive into Ancient Greek religion and prayer. According to Merriam-Webster, an epithet is “a characterizing word or phrase accompanying or occurring in place of the name of a person or thing”. Most epithets come after the name of the god or goddess, but there are exceptions to this rule (like Φοῖβος Apollon, or Phoibos/Phoebus Apollon).
When it comes to divinities, there are two types of epithets: toponymic and functional. A toponymic epithet is a place-name (ex: Apollon Δηλιος, or Apollon of Delos). A functional epithet describes a specific aspect or association of the deity in question (ex: Apollon Αλεξικακος, or Apollon Alexikakos, who was called upon to avert evil).
Epithets were generally used during prayer and sacrifice to specify the particular aspect of the god one was sacrificing to- you wouldn’t want to call upon Apollon in his plague aspect when you were praying for healing! In The Iliad, we can see an example of prayer using epithets when Chryses prays to Apollon (1.43-49). He describes Apollon as “God of the Silver Bow” and “Smintheus, god of the plague”. Both of these are functional epithets that describe Apollon and his plague aspect.
Generally, epithets are heavily used in prayers. However, the Theoi will NOT punish or ignore you for using the wrong epithet. There is only one documented case in which someone suffers because they sacrificed to the wrong aspect of a god: in Xenophon’s Anabasis, Xenophon is warned by a seer that he is suffering bad financial luck because he is only sacrificing to Zeus Βασιλευς (Basileus) and neglected Zeus Μειλιχιος (Meilikhios).
Personally, I use the tricolon style of prayer prevalent in Ancient Greek literature. However, it is my personal opinion that you have the liberty of deviating outside the general “formula” of prayer, and this freedom is protected by the cycle of Χάρις that you have built with the Theoi.
Besides the sources I mentioned in the post (The Iliad and Anabasis), I referenced Simon Pulleyn’s Prayer in Greek Religion (which I highly recommend for people interested in the subject), and the article “Epithets, divine (Greece and Rome)” by Sylvain Lebreton. In addition, I used the Theoi.com articles on epithets of Apollon and Zeus.