Greek soter, from sozein (to save, preserve, keep alive): deliverer from danger, disease, or disaster. Homer uses it for protectors; city-states voted the title to benefactors and generals; the LSJ entry lists Zeus, Apollo, Hermes, Asclepius, the Dioscuri, and even philosophers, Epicurus was hailed as soter by his followers.
The assumption Christianity quietly enforces: that savior is a distinctively Christian word minted for Jesus. The epigraphic record says otherwise, the title was common coin of the Greek world, and the gospels' use of it was a claim staked in occupied semantic territory.
Soter never meant rescuer-from-hell first; it meant preserver, from disease, shipwreck, siege. Salvation began as maintenance: keeping a body, a city, a voyage intact. The theological inflation came later; the root stayed municipal.
When did savior stop meaning the guy who fixed the harbor and start meaning the one who fixed the soul?