Of especially significant influence upon Judaism were the Persian views of Zoroastrianism. This was a philosophy which began in Persia about 600 B.C., and was growing in popularity when Judah went to Babylon / Persia in captivity. This philosophy posited that there was a good god of light (Mazda) and an evil god of darkness (Ahriman). The well known passage in Is. 45:5-7 is a clear warning to the Jews in captivity not to buy into this- Israel's God alone made the light and the darkness, the good and the "evil". But Isaiah is in fact full of other allusions to Zoroastrian ideas, seeking to teach Judah the true position on these things. Thus it was taught that "Saviours will come from the seed of Zoroaster, and in the end, the great Saviour", who would be born of a virgin, resurrect the dead and give immortality (1). These ideas are picked up in Is. 9:6 and applied prophetically to the ultimate Saviour, Jesus- as if to warn the Jews not to accept the prevalent Persian ideas in this area. Indeed, it appears that [under Divine inspiration] much of the Hebrew Bible was rewritten in Babylon, in order to deconstruct the ideas which Israel were meeting in Babylon (2). Hence we find Persian-era phrases in books like Job, which on one level were clearly very old Hebrew writings, and yet have been edited under a Persian-era hand. The Jews were also influenced by the Zoroastrian idea that somehow God Himself would never cause evil in our lives- and therefore, God is to be seen as somehow distanced from all good or evil actions, as these are under the control of the good and evil gods. Zeph. 1:12 warns against this Persian view: " I will search Jerusalem with lamps; and I will punish the men that are settled on their lees, that say in their heart, Jehovah will not do good, neither will he do evil". The fact is, God personally is passionately involved with this world and with our lives; and so it is He who brings about the dark and the light, good and evil.
Ahriman, the Lord of Darkness, is portrayed in Persian bas reliefs as having wings- and hence Satan came to be depicted as having wings, even though the Bible is utterly silent about this. According to Zoroastrianism, Ahriman envied Jupiter / Ohrmazd, and tried to storm Heaven. This mythology was eagerly adapted by the Jews to their myth of some rebellion in Heaven, and was later picked up by writers such as Milton and made standard Christian doctrine- even though the Hebrew Bible is utterly silent about it. It has been commented by a careful, lifelong student of the history of the Devil idea: "In pre-exilic Hebrew religion, Yahweh made all that was in heaven and earth, both of good and of evil. The Devil did not exist" (3).
Especially during their captivity in Babylon, the Jews shifted towards understanding that there was actually a separate entity responsible for disaster. "Much of Judaism adopted a dualistic worldview, which led it to see human problems... as the result of machinations by superhuman powers opposed to the divine will. This view infiltrated Jewish thinking during the time of the exile of Israel in Babylon" (4). "The idea that demons were responsible for all moral and physical evil penetrated deeply into jewish religious thought in the period following the Babylonian exile, no doubt as a result of the Iranian influence on Judaism" (5). Hence Isaiah 45:5-8 warns them not to adopt the views of Babylon in this area, but to remain firm in their faith that God, their God, the God of Israel, the one and only Yahweh, was the ultimate source of all things, both positive and negative, having no equal or competitor in Heaven. This becomes a frequent theme of second Isaiah and other prophets who wrote in the context of Israel in captivity. But whilst Judah were in captivity, the Jews began to speculate upon the origins of the Angels who brought calamity, and under Persian influence the idea developed that such Angels were independent of God. The Jews went further and concluded that "the destructive aspect of God's personality broke away from the good and is known as the Devil", going on to develop the Jewish legends of a personal Satan [or Sammael] with 12 wings, appearing like a goat, and responsible for all disease and death (6). The Jews of course were monotheists, and these ideas were developed in order to allow them to believe in both one God, and yet also the dualistic, god of evil / god of good idea of the Persians. It was in this period that the Jews fell in love with the idea of sinful Angels, even though the Old Testament knows nothing of them. They didn't want to compromise their monotheism by saying there was more than one God; and so they set up the 'evil god' as in fact a very powerful, sinful Angel. And this wrong notion was picked up by early Christians equally eager to accommodate the surrounding pagan ideas about evil.
The Old Testament, along with the New Testament for that matter, personifies evil and sin. However, Edersheim outlines reasons for believing that as Rabbinic Judaism developed during the exile in Babylon, this personification of evil became extended in the Jewish writings to such a point that sin and evil began to be spoken of as independent beings. And of course, we can understand why this happened- in order to narrow the gap between Judaism and the surrounding Babylonian belief in such beings. Edersheim shows how the Biblical understanding of the yetzer ha 'ra, the sinful inclination within humanity, became understood as an evil personal being called "the tempter" (7).
It needs to be understood that the Persians weren't the first to adopt a dualistic view of the cosmos- i.e. that there is a good God and who gives blessing and positive things, and an evil god who brings disaster. The Egyptians had Osiris as the good god, and Typhon as the evil god. Native Indians in Peru have Carnac as the good god, and Cupai as the evil god; the early Scandinavian peoples had Locke as the evil god and Thor as the good one; the Eskimos had Ukouna the good and Ouikan the evil (8). The Sumerian Gilgamesh epic had the same idea- Gilgamesh and Huwawa stood in opposition to each other. This thinking is totally human- it rests upon the assumption that our view of good and evil is ultimately true. The Biblical position that humanity is usually wrong in their judgments of moral matters, and that God's thoughts are far above ours (Isaiah 55) needs to be given its full weight. For frequently we end up realizing that what we perceived as "evil" actually resulted in our greater good- Joseph could comment to his brothers: "You thought evil against me [and they did evil against him!], but God meant it unto good... to save much people alive" (Gen. 50:20).
Dualism in the form which influenced Judaism and later apostate Christianity is really proposing two gods. Yet the Bible is emphatic from cover to cover that there is only one God, the Father, the God revealed in the Bible. This leaves no space for a second god or a bad god. Here we come right up hard against why this matter is important to any Bible-believing person. Helene Celmina was a non-religious Latvian imprisoned in the Soviet gulag. She later wrote of her fellow prisoners who were Jehovah's Witnesses- and word for word I can identify with her reflections here: "... I remember, too, another conversation I had with the Jehovah's Witnesses about the gods. They insisted that there were two gods, Jehovah and another [Satan], whom Jehovah would fight. No matter how hard they tried, using modern science, chemistry, and the newest findings in physics, they could not prove the existence of the other god to me" (9). These are the words of a woman who was incarcerated in one of history's most evil and abusive systems- but it didn't make her believe in the existence of a 'second god', but rather it brought her to believe more strongly that the one true God is the only God. Solzhenitsyn, as we shall later remark, learnt the very same lesson from the same gulag.