From the back cover:
Source of All Divine Power
The names of Pelor, Loki, Athena, Osiris, and their kind are invoked by the devout as well as the desperate. With abilities that reach nearly beyond the scope of mortal imagination, the splendor of the gods humbles even the greatest of heroes.
This supplement for the D&D(R) game provides everything you need to create and call upon the most powerful beings in your campaign. Included are descriptions and statistics for over seventy gods from four fully detailed pantheons. Along with suggestions for creating your own gods, Deities and Demigods also includes information on advancing characters to godhood.
New Gods on the Block