Beliefs of Zoroastrianism
Zoroastrianism is a highly ethical religion because of the struggle to choose between good and evil, Ahura Mazda or Angra Mainyu. "Zarathustra taught that humans are free to choose between right and wrong, truth and lie, and light and dark, and that their choices would affect their eternity and destiny" (Facts). The 12 000 year long battle between the two, with Ahura Mazda always having the upper hand.
There is a belief in afterlife, and it is determined by the balance of good and evil deeds, words, and thoughts. If good out weigh the bad, after life is heaven. If the bad out weight the bad, then that means you go to hell. Hell has different levels dependent on how bad your actions were. When the person dies, the soul goes on a journey on the Bridge of the Separator, along with the guardian spirit. The bridge will widen if the person has done righteous deeds, and goes to heaven. If it narrows, then the person has done evil deeds. which means they "tumble off the bridge into the abyss of hell." (Exploring). They also believe in angels/demons, resurrection of the body, and a messiah figure.
The Zoroastrian creed is "Good Words, Good Thoughts, and Good Deeds." They recited this while tying the kutsi around their sudreh three times, one for each statement. They normally practice this ritual several times a day with prayer. There is another creed found in the Yasna that can be found here : http://www.avesta.org/yasna/y12j.htm