Keep in mind - I'm certainly not a religion expert. I looked up many terms, but the information I offer includes my own interpretations and thematic suggestions as well as technical definitions.
communion - Christian ritual of the Eucharist. Also refers to connection or closeness (spiritual or otherwise), as in "to commune" (with someone/something).
mazel tov - Hebrew, Yiddish; lit. "good fortune"; today means something like "congratulations" or "felicitations."
covenant - an agreement between two parties (religiously, often a contract between God and humans). A sacred or revered contract.
benediction - a blessing, a sending-off or sending-out.
karma - what goes around, comes around. The universe/God/etc. repays you for your bad or good deeds in kind. Divine retribution.
exodus - the departure of a large number of people from an area or country. Border-crossing, escaping slavery for freedom.
lamentation - to lament is to mourn, to grieve, to articulate a loss or sadness.
shalom - Hebrew, lit. peace; also: wholeness, harmony, general sense of wellness. In Hebrew, is used as a greeting (i.e., peace be upon you). Can apply to individuals or to communities.
messiah - savior figure.
purgatory - place in the afterlife for those who were neither overwhelmingly good or evil, where one can work off their sins to enter paradise; also: waiting place, limbo, stuck in the middle; stagnation; no forward motion.
haram - Arabic word to describe any action or thing (person, object, or place) that is against the laws of Islam and Allah. Forbidden, unclean.
zen - to achieve enlightenment through meditation; the state of enlightenment. Nonplussed; calm; collected.
supplication - plea for help, especially in prayer or from a higher authority figure.
yezer ra - Hebrew, the (sinful) impulse to satisfy one's own needs, in Judaism.
nirvana - Buddhist state of enlightenment; transcendent state where there is neither suffering nor desire (since desire is what causes suffering).
Mecca - city in Saudi Arabia; one of the Muslim pillars of faith is to undertake a hajj (pilgrimage) to Mecca during one's lifetime (if possible). Has also come to mean any place that has come to be important or central to a given group of people.
alms - giving to the poor/those who need help.
catechism - a book or basic manual outlining a set of principles (from the Catholic catechism); also, a set of questions designed to determine knowledge.
penitent - regretting past sin and willing to change.
dogma - a set of principles laid down by an authority as unquestionably true.
genesis - the beginning of all things; the creation.
apocalypse - the end of the world (as we know it!). This doesn't have to be taken literally (though I do love myself a good apocalypse!fic), but could be something earth-shattering, the world figuratively falling down around your ears.
desecrate - a very strong word, meaning to treat a sacred place or thing with disrespect, scorn, or contempt; to violate the sanctity of someone/someplace/something.
sanctuary - a place with two connotations: a) a sacred or holy place; b) a refuge, a place of safety, a haven.
atonement - to make reparations or do penance for a past injury or wrong.
forbidden fruit - the apple in the Garden of Eden. Temptation; taboo. The lure of the forbidden.
Your stories do not have to be overtly spiritual. Stories about characters' religions or spirituality are, of course, also welcome, but it is definitely not a prerequisite. The prompts were chosen for their spiritual connotations and themes, but your stories do not have to be religious in ANY WAY WHATSOEVER. The words are just a starting place, and you can use them (or abuse them!) in any way you want.
So, you might think about what these themes and words could mean in a secular context. What might "repentance" mean in a fic? A change of heart? Regret for a past action? Guilt? And for the prompt Priest, for example, you might think about a leader and followers, the function of a priest (to absolve), confession, or any number of other secular, related ideas.
The prompts are just a way to get you thinking about certain themes, desires, and practices in preparation for writing.