One cause of corruption in religion…

"Nay, one cause of corruption in religion is the refusal to follow the course of doctrine as it moves on, and an obstinacy in the notions of the past. 

Certainly: as we see conspicuously in the history of the chosen race. The Samaritans who refused to add the Prophets to the Law, and the Sadducees who denied a truth which was covertly taught in the Book of Exodus, were in appearance only faithful adherents to the primitive doctrine. 

Our Lord found His people precisians in their obedience to the letter; He condemned them for not being led on to its spirit, that is, to its developments. The Gospel is the development of the Law; yet what difference seems wider than that which separates the unbending rule of Moses from the 'grace and truth' which 'came by Jesus Christ?'"

St. John Henry Newman, An Essay on the Development of Christian Doctrine