Islamic monotheism absorbed Iranian dualist notions of a cosmic clash.

Evidence

In Islam the notion of the enemies of God assumed a much greater role. The Qur’an is of course strictly monotheistic, and recognizes one God, one universal power only. There is, according to the Qur’an, a struggle in men’s hearts between good and evil, between God’s commandments and the tempter, but this is seen as a struggle ordained by God with its outcome preordained by God. It is a struggle that serves as a test of mankind, and not, as in some of the old Iranian dualist religions, one in which mankind has a crucial part to play in bringing about the victory of good over evil. Despite this monotheism, Islam, like Judaism and Christianity, was at various stages in its development influenced by Iranian dualist notions, by the idea of a cosmic clash of good and evil, light and darkness, order and chaos, truth and falsehood, God and the Adversary, variously known as devil, Iblis, Satan, and other names. — Bernard Lewis, From Babel to Dragomans, 1531

Categorization

• DEFINE: Clarifies how the ‘enemies of God’ polarity enters Islamic theology despite strict monotheism — a dualist inheritance reshaping a monotheist frame.