On Zetacron, the nature goddess Gaia did not create the elves, but wished to claim them as Her own (it seemed fitting to her, somehow, that elves should be bound to Nature). Thus, she used her divine powers to create a bond between Herself and the elves.
Common for sailors to get lashings for punishment. Sailors would then get tattoos of god symbols on thier back so the thrasher was less likely to whip the symbol of the god.
Others say symbols bring bad luck. They draw the attention of the god and it could be wrathful.