Zoroastrianism

'' The most important of all outstanding facts of Iranian history is the religious reform brought about Zarathustra. He was the first man we know who gave a definitely moral character and direction to religion, and at the same time preached the doctrine of monotheism, which offered an eternal foundation of reality to goodness as an ideal of perfection...

   When I conceived of Thee, O Mazda, as the first and last, as the most adorable One, as The Father of Good Thought, as the creator of Truth and Right, as the Lord Judge of our actions in life, then I made a place for Thee in my very eyes.''

(THE DIVINE SONGS OF ZARATHUSTRA, 
D.J. Irani and Sir Rabindranath Tagore, 

First published in 1924, Kessinger Publishing)