There's a bit more of a causal relationship there I think, as a trident is traditionally a fishing tool.
The helmet on the other hand I dunno, maybe people were really into the idea of the skeleton war?
Hades is also connected with wealth and gems and gold. So really the three god brothers in Greek mythology represent the three oldest industries: Poseidon represents hunting and agriculture, Hades mining and smithing, and Zeus... well...
Satan’s pitchfork is literally Poseidon’s trident. The image of the pitchfork-wielding goat-legged Satan is an amalgam of figures from religions the Christians wanted to vilify so that they could convert their members.
I’m not saying there can’t be some truth to the statement- often modern fictions draw from earlier ones, and Christianity is theorized to have “incorporated” or at least paralleled traditions and themes from all throughout history. That said- it is unlikely. Jefferey Burton Russel is a historian who’s well known for work on demonology of the European Middle Ages and is one of the only credible sources for the Satan/Poseidon trident link directly.
That said- we have to look at “the Devil.” Much of what is believed or portrayed in fiction and religion about the devil isn’t in the Bible or other canonical sources. You won’t find fire and brimstone or contracts for souls or a red guy with a beard and pointy horns and a pitchfork/trident in the Bible. In fact- for a great long time hell was said to be freezing cold- not burning hot.
Dante and his inferno are a major influence on popular and religious ideas of the devil and hell- but one of the first recorded images of the devil with a three pronged staff comes from about 1,000 years AD. The formalized Christian “devil” in physical form was primarily developed through the Middle Ages.
Prior to this period it wouldn’t be a pitchfork as Roman pitchforks had 2 prongs, the Europeans inherited this design and added a third for the heavy work they routinely did. A key difference between trident and pitchfork are barbs at the ends of the prongs. Barbs are for hunting/fishing to capture prey, no barbs is for moving agricultural product.
The pitchfork was a much more common implement to Middle Ages Europe, and monasteries tended to be near peasant farms. Some theorize that this is where those early monks who were creating a “physical devil” would more likely draw inspiration. Ancient Christians often had to compete with ancient religions- but it’s far more questionable that the monks of the Middle Ages would have both the need to compete with an ancient religion- but would draw inspiration from it. A the fall of Rome (it left Western Europe about 5th century round numbers-) the dominant religion was already Christianity- and in Western Europe the local religions to compete with were not those of the ancient Mediterranean primarily but religions like Druidic and shamanic beliefs etc
Now- there are some themes found common through much religious iconography. Wings- devil, demons- they have em. Angels are often portrayed as winged humans (despite canonical descriptions of wheels of fire and such...) but Hermès, the ancient gods of Zoroastrian and Sumerian beliefs- we commonly see wings as symbols of power, divinity, fertility, etc. 3’s are big. In Christianity 3 has much significance- but we see 3’s often in religion. 3 brothers of Greek mythology, 3 points to the trident/pitchfork- too much to list. Look it up. 3’s are big in symbolism. “Death comes in 3’s” etc. etc. 3 often symbolized “all” as in “heavens, sea, earth.”
Horns are another big and recurring symbol in mythology, as are hooves, goats, etc. etc. So undoubtedly the concept of the devil was influenced by many sources- it was invented, not something from “ancient source material” as a characterization to give the abstract idea of the devil physical form and a “face” for people to picture beyond a name and a vague evil.
That said- another common theme of mythology is that rich is good, poor is evil. It’s rare to have a “poor” hero who stays poor and isn’t just introduced as a poor person waiting for their chance to become a rich hero. We usually see the already well off- knights and lords and famed such and suches etc. and sometimes get to see an “Everyman” make the journey to being rich.
But opulence is seen in historical and modern religion. Bad places “hells” and “purgatories” tend to be spartan. Good places are lavish. The gods usually live in a temple, a palace, a castle. The evil gods- the devils-even when wealthy beyond imagine tend to be shown living in drab sparse and otherwise non opulent conditions.
Even in 2019 the idea that the wealthy and opulent are inherently good is quite popular. The idea that “honest” reward doesn’t come to those who aren’t deserving- or that fortunes are made entirely on the character and efforts of the individual- very popular ideas. While exceptions exist- churches and temples and the like through history have tended towards opulence. Even simple ones often had alters and idols of fine craft or gold, preachers in finery and jewelry, even the “modest” look of many robes was to show humility but the robes themselves were often expensive and well made.
It fits the religious doctrine of Middle Ages Christianity that the poor be controlled and tolerated while the rich were the main audience, the “hand that feeds.” It is generally through the wealthy and powerful that religions thrive or even exist. To offend a monarch could bring ruin to a religion- outlaw, loss of power and status. To be condoned and embraced by those in power brings influence, security, the ability to spread.
We see in Christianity for example many variations with the same core ideas that one should be beholden to an earthly representative of god, to treat this representative or their authority and laws as though they were an extensions of gods will and so on. Stability tends to be important to the administration of an established religion and it also is important to entrenched wealth or power. The two share that in common and so a partnership tends to be natural.
As such- a “pitchfork” or peasants implement shows Satan is beneath the righteous. It isn’t a fine sword- a weapon in the West and many other places traditionally more associated with wealth. So there is support that it is a pitchfork in that convention as well.
So in horror there’s this idea of not showing the monster or showing it less to make it scarier. That’s effective in film but it doesn’t work so well when you’re selling something. The European Christians needed a devil that was otherworldly and grotesque- but not so foreign and strange to be beyond relation of most men. They needed a physical symbol for evil as the two main schools of Christianity either rely on people feeling bad about hurting gods feelings; or fear of eternal suffering and damnation. The concept of being tortured for eternity is already pretty abstract. A teen aged can’t really understand the idea of 2 decades because they’ve never lived that long right? So they needed something to point st and say: “behave or the goat with a stick will get you...”
Tl:dr- for sure the devil could have been directly or indirectly influenced by ancient myths. Many things are common around the world in mythology throughout time. It’s just unlikely the devil got a three pronged stick because of Poseidon. The physical devil in the West was invented through the Middle Ages. One of the earliest images of devil w/stick is from the 10th venture AD. Rome fell and was out of Western Europe around 5th century. Rome was Christian when it fell- for 200 or so years. Before that Rome’s main religion was Mithraism- an actual competitor to early Christianity which we can see direct “jabs” at in the Bible. It’s less likely monks of the Middle Ages dug back 1,000 years for a trident and to fight a dead religion- and more likely they used inspiration of the modern era- the pitchfork. That said- many of these themes and symbols are commonly seen or even borrowed all through history.
@scatmandingo- lol. Well- I’ll make that brief- but Pacino fits the sort of image of the devil crafted in the time period and refined later. He also shows the changing values of society- where we see in certain periods of places the dynamic between rich being associated with “good” being broken. In western society we have created “poverty morality” which suggests the “poor” are good and the rich inherently evil. Our villains in fiction are often wealthy or elaborate and our heroes are often plain and modest in comparison. So Pacino takes some of the classic devil cues (contracts being on the nose...) and adds a modern morality where absolute ambition and wealth are seen as doorways to evil.
The helmet on the other hand I dunno, maybe people were really into the idea of the skeleton war?