iconoclast

Short definition from Wiktionary

Noun

1. 1
   One who destroys religious images or icons, especially an opponent of the Orthodox Church in the 8th and 9th centuries, or a Puritan during the European Reformation.
2. 2
   One who opposes orthodoxy and religion; one who adheres to the doctrine of iconoclasm.
3. 3
   One who attacks cherished beliefs; a maverick.