VEry articulate and right on.
A religion that was widely practiced in the time of the rise of Mohammed, Zoroastrianism, was generally considered to be "monotheistic", but contained a "duality" spirit.
Ahura Mazda is not the only god in the universe of Zoroastrianism, and he is not the sole creator of the world. Ahura Mazda is the father of two twin spirits, Spenta Mainyu and Angra Mainyu. The former is the holy spirit, the latter, the destructive one, and is also known as Ahriman. It appears that Ahura Mazda came to be identified with Spenta Mainyu.
"Ahriman" is probably closer to what we consider to be "Satan", and in many aspects, tends to resemble the manifestation of "Allah" to Mohammed. It is known that Mohammed considered it his divine duty to utterly destroy the Zoroastrians in Persia. A small remnant of this religion still exists in India.
Mohammed did not invent a religion. He perverted one that was already there. The guy must have been a screaming schizophrenic. That would certainly explain a lot, the "visions of God", the rages, the total inconsistencies, and the rationalizations for what we would consider to be perversions today.
The Koran is the composition of a madman. I do not care if the Muslims learn that I have made such an assertion. Apparently, they cannot, or will not, examine the basic tenets of their religion, and as such, shall never go through any internal "Reformation".