The Divine and the Devoted (2001)

From Introduction:

The Divine and the Devoted is a collection of thirteen religions for any fantasy campaign. While originally designed for the Mythosa setting, the gods and goddesses presented here can easily be dropped into other worlds.

The religions herein are given enough detail to allow you to use them in your own game, but leave plenty of room for your own modifications. In addition, the specifics of each religion’s priesthood are included, so clerics (and druids and paladins) of these gods can be put into play right away.

Religion in Mythosa isn’t restricted to only thirteen deities. There are other beings that are worshipped as well, including demigods and fearsome abominations, but these gods are the most powerful and the most popular. They are collectively referred to as the “Awakened,” as some scholars and sages believe that other entities of like power exist, but have yet to gather enough worshippers to achieve full godhood.