Moses owes many of his ethical ideals to Zarathustra

According to J.M. Chaterjee (“The Ethical Conceptions of The Gathas,1934), when the Jews were taken in conquest into the court of Nebuchadnezzar, they reformed their religion along Zoroastrian lines. Jews spent two generations among Zoroastrians and returned with most of the material for the Old Testament. Some people have even thought that Abraham was Zarathustra. 

Moses seems to owe many of his ethical ideals to Zarathustra. Joshua reformed the community from Egypt to the older religion of Zarathustra. When Moses led his people out of Egypt in the 13^th century BC into Palestine Zarathustra was already seen in inscriptions of the 14^th century. Worship of God at Sinai follows the train of Zarathustra. 

The Jews learned from the Iranian religion of Zarathustra the idea of the celestial hierarch, the idea of duality, temptation by the devil, the concept of non-idolatry, non-symbolical image worship, or the good-evil nature of deity, Resurrection, the concept of heaven and hell, and the evil spirit. 

The Iranian religion of Zarathustra continues the same since its founding with no abrupt change or breach with the past. Zarathustra largely agrees with the ancient Proto-Indo-European classics since the Rig Veda. 

Christianity developed from this Zoroastrian/Jewish history. I think Buddhism too might have influenced the Jewish sect of the Essenes concerning piety, celibacy, the absence of personal property and of money; Simon J. Joseph said the influence of Essenes can be detected in the pages of the New Testament.