Discover the Power of Faith
The flavor of clerics and other divine classes has always been that their spellcasting ability comes directly from their deity, and is a gift bestowed upon them in exchange for their faith, or else to allow them to do holy work in the deity's name. Despite this flavor, however, clerical spellcasting and other abilities rarely feel especially divine in origin, with little in the rules of the game to differentiate them from wizards, besides their ability to wear armor.
A Necromancer's Grimoire: The Book of Faith endeavors to end that problem by introducing the priest class. The priest is an alternative to the cleric, who uses new mechanics, favor and piety, to govern his class features, with game mechanics to help reinforce the personal relationship the priest has with his deity, and to reward players who do a good job of roleplaying their character's faith.
In addition to the class, and extensive guidelines on using the piety system in your game, the book also provides a number of miracles, which are new spell-like abilities that allow particularly pious priests to perform magic on a scale that most characters are unable to. Finally, the devoted apostle prestige class allows clerics and other divine casters to get a sample of the fun that the new piety mechanic can bring.
From the makers of Liber Vampyr: Secrets of the Blood and A Necromancer's Grimoire: Marchen der Daemonwulf, this book is the answer to every gamer who's ever wished that divine casters would feel a little more...divine.