Over the past century of popular culture, Satan has acquired the souls of delta blues musicians, incited youth rebellions, possessed small children and goats, impregnated unsuspecting women and transmitted evil through backwards lyrics on heavy metal records. But recently, to paraphrase the Rolling Stones, the nature of his game has been puzzling us.

The forces aligned against Satan have become so objectionable that he no longer looks like the bad guy. They include such groups as the Westboro Baptist church, notorious for its hate speech against LGBTQ people, Jews, Muslims and other groups, all of which it condemns as “satanic frauds”. There’s the Trump administration, in league with the US religious right, which has been aggressively pushing anti-abortion and anti-LGBTQ legislation, not to mention engaging in overt Islamophobia. Those forces would also include the 20,000 people who recently signed an online petition condemning the Amazon TV adaptation of the cult novel Good Omens – about a demon and an angel – as “another step to make satanism appear normal”.

Now, a documentary threatens to rehabilitate Satan. Directed by Penny Lane, Hail Satan? follows the early adventures of the Satanic Temple, an institution that has hit upon the perfect counter-strategy to the evangelicals’ efforts to recouple church and state. Based in Salem, Massachusetts (where else?), the Satanic Temple is officially recognised as a tax-exempt religious organisation. As such, it has been claiming the same rights and privileges as those obtained by evangelical Christian groups – albeit with a prankster sensibility.

Where the city council of Phoenix, Arizona, began its meetings with a Christian prayer, for example, the Satanic Temple demanded that satanic prayers should also be said. The council chose to drop the prayers altogether. When the Child Evangelism Fellowship set up the pro-Christian Good News clubs in US public schools, the Satanic Temple introduced its own After School Satan clubs – promoting scientific rationalism. And when the Oklahoma state capitol permitted the installation of a Ten Commandments sculpture in its grounds, the Satanic Temple campaigned to erect its own 8ft-high statue of Baphomet, the goat-headed, cloven-hoofed deity.

“It became very apparent that there was a real need for what we were doing,” says Lucien Greaves, the Satanic Temple’s spokesman and de-facto leader. “More and more, they try to whittle away the rights of others and define us as a Christian nation, to the extent that religious liberty applies to them alone. That’s just a scary circumstance for us to be in.”

Greaves is exactly what you would expect the earthly ambassador of Satan to look like. Pale-skinned, well-groomed and dressed entirely in black, and with one clouded eye, he could have walked off the set of a teen vampire series. Harvard-educated, he often sounds as if he is reading from an academic text. There is no mention of God in the US constitution, he points out, but there is a first amendment protecting freedom of expression and religion. The words “under God” were added to the US pledge of allegiance in 1954, and “In God we trust” first printed on US currency in 1956 – so as to differentiate the US from the godless communists. “Up to that point, it had been E pluribus unum – ‘from many, one’ – which was a much better motto.”

The Great Beast: the occultist Aleister Crowley. Photograph: Rex/Shutterstock

Greaves doesn’t believe in God, Satan, “evil” or anything supernatural, he says. Nor does he sacrifice babies or serve a secret coven. The Satanic Temple is nontheistic, and its principles are broadly liberal humanism. The first of its seven tenets, for example, is: “One should strive to act with compassion and empathy towards all creatures in accordance with reason.”

So why call it “satanism”? “The metaphor of Satan is just as important to a lot of us as it would be to anybody who takes it literally because we grew up in a Judaeo-Christian culture. It really does speak to us in a very pointed and poignant way about our place in our culture and what our affirmative values are … and, of course, it defines what we oppose: these kinds of theocratic norms and authoritarian structures.”

The Satanic Temple’s interpretation is closer to that of Milton’s Satan in Paradise Lost, Greaves says. “The rebel against tyranny, who stands in stark contrast to that mindless superstition and that mob mentality that causes people to give themselves the moral self-licensing to create the ‘other’… and thereby victimise people.”

You could say that is in keeping with Satan’s place in pop culture. Only occasionally has he been taken as a literal figure of evil; more often, the devil represents the outsider, the provocateur, the one with the best tunes. To be labelled “the devil’s music”, as jazz, blues and rock’n’roll all were, was the best possible branding. The Rolling Stones expressed their Sympathy and called an album Their Satanic Majesties Request, but nobody considered them serious satanists. Led Zeppelin’s Jimmy Page would have been more qualified; he inserted mystical symbols into the band’s imagery, owned an occult bookshop in London and was a keen collector of the works. He even bought the Scottish home of the occultist Aleister Crowley (whose face also appears on the cover of the Beatles’ Sgt Pepper album). Page collaborated with the film-maker Kenneth Anger, whose films of the era, such as Lucifer Rising and Invocation of My Demon Brother, brought together a Who’s Who of 60s occult-dabblers, including Page, Mick Jagger, Donald Cammell, Marianne Faithfull, the Manson family member Bobby Beausoleil, and Anton LaVey.

LaVey is acknowledged as the founder of modern satanism, although he, too, was more theatrical showman than genuine prince of darkness. He strove to look the part, with his shaved head, sharp little goatee and black cloak – imagery largely gleaned from old horror movies. He opened the First Church of Satan in San Francisco in 1966, synthesising various occult sources into a semi-coherent philosophy, and attracting a few celebrity devotees, including Jayne Mansfield. Greaves acknowledges the Church of Satan as an influence, but rejects LaVey’s beliefs in social Darwinism and police-state authoritarianism as “Ayn Rand with ceremonial trappings”.

Norwegian black metal band Mayhem. Photograph: Publicity.

The heavy metal acts of the 1970s and 80s caused more alarm in some quarters, from Black Sabbath and Coven onwards through the likes of Slayer, AC/DC, Iron Maiden and onwards to thrash, death and ultimately black metal. Again, the satanic messaging was largely theatrical: occult symbolism, demonic lyrics and horror-movie guitar riffs. The exception was the infamous Norwegian black metal scene, which devolved into genuine horror with the bands Burzum and Mayhem, whose horrific saga involved church-burnings, suicide and murder. “A lot of these movements have always had an inordinate amount of attention for how small they really are,” says Greaves. “Sometimes, they embraced the worst elements of what they were accused of. They become this creation of the hysteria against satanism.”

That hysteria rose to witch-hunt levels in the 1980s and 90s, in what became known as the “satanic panic”. Doubtless inflamed by the imagery of horror movies, such as The Exorcist and Rosemary’s Baby, Christian groups began finding “evidence” of satanism everywhere. They heard subliminal satanic messages in rock records, the most famous being Led Zeppelin’s Stairway to Heaven (which supposedly contains the phrase, “Here’s to my sweet Satan,” when played backwards). Then came lurid allegations of satanic ritual abuse around the world – child sexual abuse, murder, torture, cannibalism and gory rituals, ostensibly at the behest of a secret sect intent on undermining the foundations of civilisation.

This is the environment in which Greaves grew up. “I saw peoples’ lives destroyed by the mere attribution of satanism,” he says. “I began to realise that the real evil was in the witch-hunt itself, and not in any of these alleged cults that were supposed to be initiating these activities.” While satanist conspiracy theories filled the airwaves, it bears remembering that there really was an organised sect sexually abusing children on a global scale with impunity: the Catholic church.

Greaves in Hail Satan? Photograph: Magnolia Pictures

Things have hardly improved in recent years, Greaves admits. Despite being led by a serial sinner, the Trump administration has been on a concerted mission to reinsert conservative Christian values into US public life. This legislative assault, known as “Project Blitz”, is coordinated and well-funded. “We’re obviously on the defensive now,” says Greaves, “and it’s a frightening state of affairs in the US when you have a clearly deranged theocrat like Mike Pence as vice-president and a buffoon like Trump in office, and they’re willing to pander to their evangelical nationalist base.”

The release of Hail Satan? is a blessing and a curse for the Satanic Temple. It should bring new members and much-needed revenue to the cause (the church’s only income is direct donations and merchandise sales), but it also puts Greaves in the limelight, possibly even the crosshairs. Towards the end of Hail Satan? we see him appearing at a satanist rally in Little Rock, Arkansas, next to the notorious Baphomet statue. Before he steps out, he puts on a bulletproof jacket.

Greaves remembers that rally well. “What you don’t see,” he says, “is when I was walking up to the podium, there were a bunch of people with guns loitering about, and they wanted me to know they were there. I ended up speaking with my back to them, which was rather harrowing. I’m kind of puzzled as to why nobody did take a shot, but that was a very clear possibility.” He regularly receives death threats from the Ku Klux Klan and neo-Nazi and Christian supremacy groups, he says, but Greaves is more concerned for his country’s future than his own. “We’re at the precipice of a new dark age,” he says ominously. Rather than ushering it in, the satanists are trying to stop it.

In the UK, Hail Satan? has preview screenings on 20 August and is released on 23 August