Prophet Zoroaster preached against idolatry worship. Rather, He emphasized that people should venerate only Ahura Mazda, the Superme Being and the absolute icon of Truth and light. Prophet Zoroaster also taught that each individual has the free will to choose, and that each soul will be personally accountable for his/her own actions. By engaging one’s free will to formulate good thoughts, words, and deeds, one will reap happiness or merit. Moreover, He highlighted the need to change the class structure of that time to give the people more liberty.