The correct answer to this open question is the following.
Although there are no options attached we can say the following.
People who fill special functions within a religion--ministers, spirit mediums, priests, diviners, imams, monks, nuns, deacons, etc.--are examples of religious specialists.
Often they are called clergy people who perform special functions in the internal operations of the church. These people are needed in different activities and play specific roles to help the church running.
Mostly, they perform activities that help the church to promote their principles and teachings in a country and around the world, because, in the end, the church is a complex organization that if compared to other organizations, should be run as a non-profit organization. So it requires professionals and specialists in its daily operations.
