A central premise of deism was that the religions of their day were corruptions of an original religion that was pure, natural, simple, and rational. Humanity lost this original religion when it was subsequently corrupted by "priests" who manipulated it for personal gain and for the class interests of the priesthood, and encrusted it with superstitions and "mysteries"irrational theological doctrines. Deists referred to this manipulation of religious doctrine as "priestcraft," an intensely derogatory term. In the eyes of deists, this corruption of natural religion was designed to keep laymen baffled by "mysteries" and dependent on the priesthood for information about the requirements for salvation– this gave the priesthood a great deal of power, which the priesthood naturally worked to maintain and increase. Deists saw it as their mission to strip away "priestcraft" and "mysteries". Tindal, perhaps the most prominent deist writer, claimed that this was the proper original role of the Christian Church.