Calling someone a rain god is making the prediction “If I worship this person, rain will occur at the times I need it more often than it would if I did not worship this person.” Worship doesn’t stop being worship just because it works.
Calling someone a rain god is making the prediction “If I worship this person, rain will occur at the times I need it more often than it would if I did not worship this person.” Worship doesn’t stop being worship just because it works.