For whatever reason, zealots have been refused any rank higher than Acolyte within the hierarchy of the Church of the Perfect Light. Sometimes at odds with the Church and sometimes in accord with it, they wander the world on their own eccentric quests. They are quick to throw themselves in harm's way and disdain ranged weapons, but in fact they are quite bad at melee fighting. Instead, parties profit most from their healing and fire magic.
The zealot has a weaker BAB than the cleric but can make up for it with more offensive spells -- all of which use fire. In addition, they are still able to keep to the front lines with access to all armor (minus plate), plus higher fortitude saves than their D&D cousins. They also have access to the Mystic and Brawler traits. Mystic attunes them to supernatural forces, making them more aware of supernatural dangers than other characters; Brawler lets them resort to fisticuffs when necessary.