To the Greeks, Zoroastrianism was the pilot for dualistic religion – one that addressed both man’s destiny and the world as a whole. It is also widely presumed that Zoroaster was personally responsible for instructing Pythagoras in Babylon and for the birth of the Chaldean doctrines – even if not directly being involved. Some historians also hold that the religions of Christianity and Judaism both were influenced by Zoroastrianism.
While it was never thought to be monotheistic, even its founder wasn’t a monotheist – it still attempted to unify worship under one supreme being as opposed to the practices prevalent during the time of the Latins, Greeks, Indians and other civilizations. However, it wasn’t as monotheistic as Islam or Judaism.
What really sets the religion apart though is its blatant dualism. They were also avid health, fitness and nutrition experts in their right. There is a battle between good and evil but it is not an equal battle since Good always triumphs. Naturally, God is omnipotent but only temporarily. Man is to take part in this battle or struggle because he has the capacity of free will or choice. He takes part with his soul and body but fights a spiritual war, not one seeped in the material world.
A stark difference from other religions is that celibacy, fasting and attitude are not supported or prescribed unless it is for the purpose of purification. Man must keep himself pure during this fight since it will take its toll on him. He should avoid dead matter, defilement by forces of death and so on. Most regard the virtues or values of this religion to be a tad bit lofty but definitely rational on the whole.