This was very helpful. Let me just clarify my thoughts a bit, and then I want to go more deeply into the issue of the nondual.
I didn’t mean to say that the dualism of God versus the Devil that seems to haunt much of Christianity came directly from Zoroastrianism. You are right that Zoroastrian ideas entered Judaism during the Babylonian exile in the latter decades of the sixth century BCE. I just meant that there seems to be a parallel view between Christian and Zoroastrian dualism.
Dualism is the great error of the western religious traditions. The pitting of God against some form of personified evil lends itself to identifying one’s enemies as being against God. The terms we use for those we oppose make this all too clear: heretics, infidels, unbelievers, etc. If God is battling with the Devil, and we are on the side of God, it just stands to reason that those who stand against us stand against God.
The idea of unbelief is so ingrained in our culture that even President Obama used it in his inaugural address speaking of Jews, Christians, Muslims, Hindus and unbelievers. There are no unbelievers, only people who believe differently.
We might sum up the entire history of Abrahamic religion as: My God is bigger/truer than your god, and I can prove it by killing more of you than you can kill of us. Body count as religious proof¬¬–text is a horrible legacy. I’m exaggerating of course, but not by much.
The solution though is not less religion but better religion. And by better I mean religion rooted in a nondual understanding of reality. Nondualism as I would define it here is the belief that all things are manifestations of a singular reality I call God. This is not the same as saying there is one God, for one only makes sense in opposition to many. The One and the many is subsumed into the larger whole that is the nondual singularity.
When Jesus says, “I am the vine, you are the branches. The one who abides in me while I abide in him bears much fruit,” (John 15:5) he is speaking in nondual metaphor. There is a clear distinction between vine and branches, and yet both are part of a single living system. We are in God and God is in us, just as the wave is in the ocean and the ocean in the wave. Similarly the Christian mystic Meister Eckhart (1260-1328) says, “the eye with which I see God is the eye with which God sees me,” again speaking to a nondual understanding of reality. Every religion has this insight, though in the west it is limited to mystics.
In nondualism good and evil are both aspects of the singular reality, God. To limit God to the good alone is to define God down from the all to the less than all. Seen this way temptation and resisting temptation is all a part of God.