I have been reading the wheel of time books from Robert Jordan and there exsistes a group that just might fit in birthright. they are called the children of the light and are a militant group of solder/priests that go around converting by the sword, stiring up the people agenst there rulers, and just making trouble. It might be interesting to take a old line church of Healyn and make them start a holy war against everyone. Start by having small groups of missionaries going out to fight briginds, or help a few communites. After a while they gey sourse holdings and start making sure everyone "walkes in the light".