In its original inception the church was initially a group of Created gathered by Corinthea to fulfill the Last Prophecy of Daeron. This group was little more than body of likeminded Unborn who after the creation of new-man in the image of old-man set about guiding the instruction of the Firstborn.
Ages Post cataclysm what is known as the second awakening The Church becomes closer to what it is today, a body of likeminded individuals but with a purpose to bring the Firstborn under the influence of their new doctrines. doctrines created after the Sermon of Ethos.
To fulfill the sermons, end the church has corralled the sentient life into cities and hamlets. were they can indoctrinate and keep them under better surveillance and gifted the Firstborn with the Blessed Medium.
Lesser magics are said by the Priesthood to be the gift of God /Gods while greater magic is to be the portfolio of the priesthood, unsanctioned magicians are actively sought as heretical until proven holy (converted by whatever means necessary)
Priestly squads of hunters are sent from the varied holy bastions to find these magicians, and in that guise look for the Reincarnation of Daeron
By the time of the true Firstborn only one institution of magic is in operation and even that has been infiltrated. all others have been obliterated from knowledge turned into churches of the One True Magick, or gone into hiding in the lost places of the world.