From the publisher:
There are priests for whom simply believing isn't enough.
They need to share their belief with others, and have those others come to believe too.
Their belief is so powerful that they can convince others of it merely by talking and sharing, so powerful that they can shift or even schism entire religions and schools of theological thought by their proclamations.
Disciples are faith healers, preachers, cult leaders and prophets. They are placed at the core of organised religion, or in direct opposition to it. Charismatic, faithful, and inspired, they are a powerful and dangerous class as much for their social influence as their actual abilities.