It is said that life giving water is the 'nectar of the gods'. These gods maybe those worshiped in Serenia, or native to the region (or at least its desert). Those who worshipped a anonymous, nameless and forgotten god at the Desert Temple (however they may simply just worshipped Pegasus). Some legends suggest they killed themselves, and their god (however Pegasus still lives).
The most power god is the creator known as God (and perhaps the only 'true God'), the rest are just minor deities.