Contribute or Contribution is a good word to describe this activity, suggesting an investment that unifies the group around a common purpose. The prefix con for together, implies the unifying principle.
1. Give (something, especially money) in order to help achieve or provide something:
from Latin contributus, past participle of contribuere "to bring
together, add, unite, collect, contribute" (see contribution).
Figurative sense is from 1630s.
Related: Contributed; contributing.
from Old French contribution and directly from Latin contributionem
(nominative contributio), noun of action from past participle stem of
contribuere "to bring together, add, contribute,"
from com- "together" (see com-) + tribuere "to allot, pay" (see
"stated sum of money or other valuable consideration paid by one ruler
or country to another in acknowledgment of submission or as the price
of peace or protection,"
from Anglo-French tribute, Old French tribut and directly
from Latin tributum "tribute, a stated payment, a thing contributed or
paid," noun use of neuter of tributus, past participle of tribuere "to
pay, assign, grant," also "allot among the tribes or to a tribe,"
from tribus (see tribe). Sense of "offering, gift, token" is first
"one of the twelve divisions of the ancient Hebrews," from Old French
or directly from Latin tribus "one of the three political/ethnic
divisions of the original Roman state" (Tites, Ramnes, and Luceres,
corresponding, perhaps, to the Latins, Sabines, and Etruscans), later,
one of the 30 political divisions instituted by Servius Tullius
(increased to 35 in 241 B.C.E.), of unknown origin.
Perhaps from tri- "three" + *bheue-, root of the verb be.
Others connect the word with the PIE root *treb- "a dwelling" (see
It is not necessary for the unifying principle of a group to be religious.