The whole religion of the Avesta revolves around the person of Zoroaster,
or Zarathustra. In the oldest part of the sacred books, the Gathas of the
Yacna, he is called the _pure_ Zarathustra, good in thought, speech, and
work. It is said that Zarathustra alone knows the precepts of Ahura-Mazda
(Ormazd), and that he shall be made skilful in speech. In one of the
Gathas he expresses the desire of bringing knowledge to the pure, in the
power of Ormazd, so as to be to them strong joy (Spiegel, Gatha Ustvaiti,
XLII. 8), or, as Haug translates the same passage (Die Gathas des
Zarathustra, II. 8): "I will swear hostility to the liars, but be a strong
help to the truthful." He prays for truth, declares himself the most
faithful servant in the world of Ormazd the Wise One, and therefore begs
to know the best thing to do. As the Jewish prophets tried to escape their
mission, and called it a burden, and went to it "in the heat and
bitterness of their spirit," so Zoroaster says (according to Spiegel):
"When it came to me through your prayer, I thought that the spreading
abroad of your law through men was something difficult."

Zoroaster was one of those who was oppressed with the sight of evil. But
it was not outward evil which most tormented him, but spiritual
evil,--evil having its origin in a depraved heart and a will turned away
from goodness. His meditations led him to the conviction that all the woe
of the world had its root in sin, and that the origin of sin was to be
found in the demonic world. He might have used the language of the Apostle
Paul and said, "We wrestle not with flesh and blood,"--that is, our
struggle is not with man, but with principles of evil, rulers of darkness,
spirits of wickedness in the supernatural world. Deeply convinced that a
great struggle was going on between the powers of light and darkness, he
called on all good men to take part in the war, and battle for the good
God against the dark and foul tempter.

Great physical calamities added to the intensity of this conviction. It
appears that about the period of Zoroaster, some geological convulsions
had changed the climate of Northern Asia, and very suddenly produced
severe cold where before there had been an almost tropical temperature.
The first Fargard of the Vendidad has been lately translated by both
Spiegel and Haug, and begins by speaking of a good country, Aryana-Vaejo,
which was created a region of delight by Ahura-Mazda (Ormazd). Then i