Google Ngram is not totally accurate, for the term “monotheism” was coined in the 1650s—and so, rather like all these graphs about climate change, who knows what spikes and troughs lie beyond 1800.
However, you get an impression as to how the concept rises and falls in popularity—with our age being more interested in monotheism than any time since the mid-Victorians.
What else starts in the 1650s? Modernity—Descartes and all that. So we should be suspicious about “monotheism”.
The fact is that Christianity did kill off all the old pagan gods, but, until the 1600s, until the Reformation, God and the Devil were really co-equals—Christianity was a di-theism, not a monotheism.
You know the image: there’s a devil on your left shoulder and an angel on your right—and one tugs your ear to drink or wolf-whistle at women (bang the chair on the floor first), and the other tells you to scrub your hands carefully after using the toilet and hold doors open for old ladies.
The Devil is an active presence in the world—he makes the milk curdle in the churn, he sent hailstorms to destroy the early crops. He must be countered through obedience to God—who, though he wins in the end, takes part in a knife-edge struggle against the forces of darkness.
It comes from Christianity’s Zarathustrian roots—the world is divided into the forces of dark and the forces of light, and these contend in a battle that is almost co-equal (although light wins in the end). In this framework, “the forces of darkness” are an almost embodied presence in the world.
Jesus was adored by the Magi—who were Zarathustrian priests who followed a star, Zarathustrians being star-worshippers and Zarathustra’s name literally meaning “star-man”. Zarathustra said he would return as a second saviour, the saoshyant, born of a virgin and attended by miracles, as Zarathustra was himself—and this saviour would end the struggle between light and darkness in favour of light.
So what the New Testament wants to say is that Jesus is the saoshyant, the son of Zarathustra. Hence this idea of two almost co-equal forces in contest is embedded in Christianity—maybe that was true, maybe the Jews who composed the New Testament deliberately played on that idea to manipulate people to follow their religion (the predicted dates for the saoshyant do not conform with the birth of Jesus but the New Testament really wants you to think he is).
Anyway, what happened with the Reformation and early modernity was that men took a serious look at this idea “God and the Devil co-equal”—and many of them were Germans. The result was, in the return to primitive Christianity and the advent of rationalism, that the Devil was abolished.
You see, there’s “one God”, right? If there’s one God, so thought the Germans, how is there this knife-edge struggle where it seems the Devil might win? It seems to diminish the one God’s power—it’s almost paganism, with all these Catholics praying to saints and martyrs to try and balance out the “living presence of the Devil”.
Hence, as with the pagan gods before, the Devil—Satan himself—was abolished. He was abolished on the same grounds as the pagan gods—he was “a superstition” (for Irish peasants and the like). He was an insult to the one God—who was omnipotent and omnipresent, as most people will say God is through the lens “monotheism”.
By the end of the 19th century, books by professing Christians talked about the Devil as a superstitious artefact that had been overcome, a joke—and by the 1950s, as men like LaVey came on the scene, actual Devil worship had become an ironic joke.
Of course, along the way, the process that started when the pagan gods were abolished as “superstitions”—so earning the early Christians the justified sobriquet “atheists”—had continued so that the “one God” itself has been abolished as a superstition. Already, by the 1770s, men like Benjamin Franklin had reduced a God who was once locked in a knife-edge conflict with the Devil to “a man who switched on the light and then rested”—otherwise known as Deism, God flipped the switch on the whole machine and nothing else.
Hence we arrive at today, where people will argue the merits of “monotheism” versus “polytheism”—especially neo-pagans and Christians. Yet monotheism is modern—and Christians today will actually retail their religion as superior because “it doesn’t have superstitions like the Devil” (such people also think “the logos” just means “reason”—not a series of magic words, because they are totally modern and don’t even know it).
Monotheism also became, per the Victorians, a sign that a society was “progressive”. So it went paganism > Christianity > science. Each step abolished more and more “superstition” and moved towards what the Victorians called “civilisation”—so that primitive tribes were primitive because they were polytheists who thought rubbing metal together summoned “the ugly spirit” and so that must be banned, whereas Christians surmounted such superstition and introduced a rule-based God and so could see when it was useful to rub metal together; and the Christian God, in the end, became “science and the laws of historical progress”.
So “monotheism” is an illusion—for most of its life Christianity was a religion where there was a real and palpable struggle between God and Devil, with things in doubt (even if it would come right in the end—which, it is true, as the Germans said in the Reformation, does cause contradictions in the belief). From the 1650s onwards, there was definitely only “the good God”—the Devil being an insult to his omnipotence, and then the good God himself was abolished too (being the final superstition).
Yet even today I see people proudly declare that as “traditional Christians” they struggle against “polytheism” and are for the superior “monotheism”. These people are not like early Christians, or even medieval Christians—they are Victorians. They are totally modern men who don’t think there’s “a devil on your shoulder” and are actually slaved into the cult of progress—of course, above all, like most people interested in these ideas, they’re unbearable egotists.
I rarely use the term “God” because the Christians and the Muslims have made it a dirty word—sometimes I use it to be more comprehensible. The word was made dirty when the Christians and Muslims conflated the Godhead with a personality—with a Semitic personality—and called it “the one true God”, a situation that, centuries later, led to the concept “monotheism”. The Godhead is the infinite, the unsayable: it is many gods, it is one God—it is both and neither.
You can clothe it in many ways, but it itself is always a paradoxic that cannot be said. If you say it is one you are both right and wrong at the same time. There are many paths to the divine—through eight gods, the ogdoad, if you wish; or through one God if you prefer. It is only selfish religions—like Christianity and Islam—that lie to you and tell you there is “one God”, the final outcome is universal atheism.
The children of the Christians—liberals, Marxists, progressives—tolerate no other religion, just as the their parents, the Christians, tolerated no one before them. The Christians cry out “We’re so persecuted!” but I say unto you, my friends, what they have done unto others has been done unto them.