Zoroastrianism, considered by many as history's oldest monotheistic religion. It greatly influenced Judaism, Christianity, Islam, Buddhism, and Greek philosophy. Founded by Zarathushtra who was born between 1800-1700 BC and lived in northeastern Iran. He saw the human condition as the mental struggle between aša (truth) and druj (lie). The purpose of humankind is to sustain aša, this occurs through active participation in life and the exercise of constructive thoughts, words and deeds.