The philosophy of dualism "Zend-Avesta"

The study of religion, like the study of poetry, brings us encounter to approach with the fundamental principles of human nature. Belief, whether it be spontaneous institution or that which is formulated in a volume, is as coupling as poesy, and equivalent genre, existed before letters and authorship. It is only in a thoughtful and kind couch of obey that we should advance the rudest forms of these two departments of hominal trait.

A systematic reasoning  of the "Zend-Avesta" suggests to us the knowledge of the Farsi sage Zarathustra, or Zarathustra, fixed upon the phenomena of nature and experience, and trying to provide a systematic account of them.He sees good and evil, life and death, sickness and health, right and wrong, engaged in almost equal conflict. He sees in the sun the origin of light and heat, the source of comfort and life to man. Thus he establishes  the  philosophy of Dualism and the adoration of Fire.
The vile things that arise unexpectedly and irresistibly, he ascribes to the Devas: the support and relief that man needs and ofttimes obtains by means which are beyond his command, he attributes to the "Hallowed Unfading Ones," who endure around the Presence of Ormuzd.

As he watches the purity of the fire, of the perspicuous stream, and of the unsoured odorous ground, he connects it with the good innocence which springs from naivete and rectitude, and in his encipher it is as reprehensible to contaminate the render by burning the dead, or the flow by committing the corpse to its waves, or the connective by making it a burial-place, as it is to betray or lie or charge an act of violence. The wonders of Nature furnish plethoric imagery for his hymns or his litanies, and he relies for his cosmology on the faint traditions of the past gathered from any land, and reduced into accordance with his Philosophy of dualism.
"Zend-Avesta" is the religious book of the Persians who professed the creed of Zarathustra, known in classic and modern times as Zoroaster. Zoroaster is to be classed with such great religious leaders as Buddha and Mohammed. He was the predecessor of Mohammed and the worship and belief which he instituted were trampled out in Persia by the forces of Islam in the seventh century of our era. The Persian Zoroastrians fled to India, where they are still found as Parsis on the west coast of India. The religion of Zoroaster was a Dualism. Two powerful and creative beings, the one good the one evil, have control of the universe. Thus, in the account of the creation, the two deities are said to have equal though opposite share in the work.This constant struggle of the two divinities with their armies of good and bad spirits formed the background of Zoroastrian super naturalism. The worship of the Persians was the worship of the powers of Nature, and especially of fire, although water, earth, and air, are also addressed in the litanies of the "Zend-Avesta."

Zoroaster taught that the life of man has two parts, that on  earth and that beyond the grave. After his earthly life each one should be punished or rewarded according to his deeds.

The "Zend-Avesta" cannot be dated earlier than the first century before our era. It consists of four books, of which the chief one is the Vendîdâd; the other three are the liturgical and devotional works, consisting of hymns, litanies, and songs of praise, addressed to the Deities and angels of Goodness.