The author, acting as Jesus aged 13, in a school version of Jesus Christ Superstar

“Do you like to shock people, Christian?” says Dr James Fox, perched on the edge of a squat sofa, straight-backed, his neck angled upwards like a dad at a service-station urinal. Just an arm’s length away, Christian Jankowski looks back, smiles, and uncrosses his legs.

It’s September 2016, I feel poorly, and I’m watching a documentary about conceptual art. I’ve no real knowledge on the subject and the film is trying to educate me. It does this in the same language as pretty much any BBC documentary of the past 80 years: polished accents offer informative and dry anecdotes; stock footage brings colour; cameras are slowly approached by presenters who gesticulate and expertly time their arguments to wrap up as they leave the frame. This is a familiar space; a comfortable one. Until the mould is broken.

Fox has interviewed other artists on the show, but this one feels different. Earlier, he was standing in the lift of a Berlin warehouse looking agitated, as a hastily added voiceover filled the room: “I’ve been told to go with the flow.”

Fox knocks on the door and it opens. A middle-aged German man answers – looking something like Tintin on his second marriage – and they shake hands without breaking eye contact. As they turn toward the studio and stroll side by side, Fox makes small talk and compliments the décor, totally ignoring the fact that the artist, Christian Jankowski, is completely naked.

The whole show is brought to a halt. What the fuck is going on? Who is this guy? What are his motivations? “I like to create images,” Jankowski says, as the two sit opposite each other looking like the Sistine Chapel ceiling stuck to an Ikea leather sofa. They begin discussing his art in earnest, the German artist casual and the presenter pretending to be. But this is a standoff, and neither will let up, so the tension builds. What minutes ago was a BBC documentary has now completely transformed, and I don’t know how I feel. Then something else happens which I didn’t expect.

I start smiling. Then I properly start laughing. And the longer both Fox and the documentary itself refuse to acknowledge Jankowski’s naked invasion, the funnier it becomes. This, I realise, is a feeling I understand. I’d mentally prepared to learn about art, but this doesn’t need to be explained. It’s instinctual.

Needing to see more, I searched Jankowski’s name and what was waiting for me was staggering. For people in the know, what had just happened wasn’t completely unexpected. Jankowski, born in Göttingen, now 52, had been creating conceptual art since the early 90s. He’s had solo shows around the world, been featured at multiple Biennales, won the Hamburg Finkenwerder prize for contribution to German contemporary art and been tasked with curating the 2016 Manifesta in Zürich to celebrate the 100th anniversary of Dada. For people not in the know, first contact with Christian Jankowski provides spectacular, hilarious images that don’t quite make sense, captured through films and photographs. A group of professional Polish weightlifters in red spandex surround a gigantic bronze statue of Ronald Reagan in Warsaw and try to lift it;a popular sports commentator bellows a combination of weightlifting statistics and historical facts over their attempt.

Ending credits roll over grainy footage of a church band playing out a service in Texas. A televangelist preacher clutches a microphone and is surrounded by a congregation in chorus. Yet by their feet is something else: a man in a pile, facing away from the camera, arms sprawled like it’s a crime scene. It’s Jankowksi. Earlier, he was invited on stage and was struck so strongly by the holy spirit that he collapsed and has been left there since. Searching through these scenarios and images, I find something in particular that illuminates my life.

Eighteen years ago, Jankowski was nosing around Cinecittà film studios in Rome when he came across a man in a trailer who made him pause. The man’s hair was long, his clothes torn to shreds, and he was completely covered in blood. This man was Jesus. Jesus was on set for Mel Gibson’s The Passion Of The Christ and was having a disagreement with doting Vatican priests – also actors – about how Jesus should express himself while being killed by the Romans. Witnessing this biblical scene in a box trailer, Jankowski was apoplectic and felt a hangover of depression that he wasn’t able to photograph the moment. For the next eight years, he couldn’t get this image or the questions it raised out of his mind: how many portraits of Jesus exist, how many are produced every year, and how does our vision of religious figures develop with time and culture? In 2011, he decided to confront this vision by returning to Rome to create Casting Jesus.

With Casting Jesus, Jankowski’s idea was simple. He planned to set up a studio in a 1,000-year-old medieval pilgrim hospital in Rome and convince high-level Vatican officials that they were judges in a TV talent show trying to cast the new Jesus. Now, as somebody who grew up the youngest in a large Catholic household, I found this idea immediately arresting. Bringing The Apprentice to the doors of one of the most ornate, historical religious institutions is absurd. Creating a context where Saint Peter and Pete Waterman equally belong is obscene. Hilarious. It’s also uncomfortable. It shouldn’t exist.

Yet taking popular, predictable formats and playing with people’s expectations of them is a device Jankowski uses often. Like when he directed an episode of an infamous Mexican telenovela soap opera, but only allowed its experienced actors to communicate by crying. All the cheap sets, overblown emotive music and predictable storylines are ignited by these actors’ sincere tears. It was so absurd that I was pinned down by laughter, genuinely feeling like I needed to take three aspirin.

But Casting Jesus was a gigantic leap further than anything Jankowski had done before. He offered his proposal with little hope… but the Catholic church responded, then actually went for it. All of a sudden, it was coming to life. A panel consisting of a Vatican executive secretary, a priest and a celebrated author were provided to slip into Simon Cowell roles. He hired a Roman acting agency to find potential Jesus contestants. This was beginning to affect real people. And picturing the earnest Jesuses, pacing back and forth in their flats, running lines from the Sermon on the Mount, it’s a valid question to wonder whose expense this is at. Or any of his work for that matter. Often – like in this circumstance – the participants are unsuspecting. Similarly, in the late 90s, Jankowski rang a slew of Italian TV fortune tellers live and asked them to predict the future prospects of himself as an artist and the current piece he was working on. They responded unevenly; showed themselves up. And some struggle to forgive him for this dishonesty.

Yet I believe 2003’s This Is I Played Tomorrow illustrates his intentions better. Every day, around 30 Hollywood hopefuls will queue outside of Cinecittà studios wanting to get into a film. One day, Jankowksi decided to talk to them. He asked about their wildest film fantasies; how they’d look in those films, what role they’d play, how they might die. He then returned to these actors with a script in which they all got to play their dream roles how they imagined, in some cases word-for-word, and shoot at those very studios. The results are fascinating, curious and bizarrely touching. This is closer to Jankowski’s ambitions. The people within it are fundamental to the piece, collaborators rather than victims.

With a location, judges, and actors ready, Jankowski’s Casting Jesus vision was ready to come to life. An audience of 300 people is packed inside a wing of Rome’s Complesso Santo Spirito, awaiting the answer to a debate which has lasted millennia: what is the definitive representation of Christ? Five minutes before the scheduled beginning, three middle aged men appear – one in a dog collar, another in a brown suit and the last in jet black – and take their seats. The lights in the studio go down as the audience watches from the auditorium. Then a spotlight reveals 13 Jesuses. Some wear crowns of thorns, others are covered in blood, all look sombre. From here on, Jankowski’s direction is over. This counterintuitive collage of madness can descend into anything, but it doesn’t. It does something even stranger. The judges take charge, and it plays out exactly like a TV talent show.

Pop culture penetrates the divine as the judges embody archetypes to direct the contestants. Each Jesus is made to break bread and perform a miracle. They must recite scriptures and recreate biblical stories. The judges are in their element, clapping and exclaiming at moments which please them and grimacing at others. One instance in particular is both confusing and depressing: a judge sees a contestant kissing somebody they’re performing a miracle on and counts it against their chances. “I hope mine doesn’t do that.”

The judges begin narrowing the selection until they have finalists. The remaining Jesuses are tasked with creating his final moments. Each Jesus must bear the cross on their back and endure a taste of his suffering. As the other candidates surround, abuse and flagellate their fellow competitors one by one, the judges deliberate among themselves. “This one is wrong,” a man in a priest’s collar says as he points at a Jesus, “because he is not suffering.” Then, it dawns on me what is playing out in front of my eyes. What the judges are trying to do. And I can’t believe, having endured the residual presence of a Catholic upbringing throughout my life, it has taken the prism of Jankowski’s reality TV show to help me fully realise the religion’s condition. The judges are trying to measure suffering. And he who suffers best gets to be the closest to Christ. Or gets to be Christ, even.

And that’s exactly what happens. The winner, as chosen by the Vatican, is a method actor named Robin who has been quietly suffering in character for weeks preparing for this. He doesn’t leave empty-handed. Jankowski enlists his Jesus in a series of subsequent projects; a smartphone picture of him taken by one of the Vatican officials is mass-produced by Jankowski and handed out as an icon; they head to Central and South America together and appear on television. Projects colliding with reality and having lives of their own beyond Jankowski’s involvement isn’t rare in his work. If you sing at any Korean karaoke bar around the world, watch the accompanying corny music videos and there’s a good chance you’ll see Jankowski acting as the typical “western boyfriend”, walking along a beach or passionately feuding with any number of Korean actresses. This is due to the result of a day’s work with a Korean company for 2003’s The Day We Met.

Given how Jankowski was catapulted into my life out of nowhere, I think, to fully understand him, why he manipulates expectation and how he plays with context, it’s important to place him in his own.

As somebody who works with media, Jankowski could quite easily work in the media. Three decades of headline-grabbing stunts would make the perfect CV. And he’d surely make more money. But no, his intentions are clear. No matter how much I remove him from his context like I have in this piece, ultimately, whatever he does, Jankowski is doing it with a destination in mind. That’s not a Mexicanan telenovela, a Christian TV channel or a BBC documentary, but an art gallery. All of the works and stunts that I’ve referred to earlier on have ended up on gallery walls in one of the major metropolises of the world. This enables him to move through the world, interacting with the same things the rest of us are, but with different motivations. Asking different questions. Like a superpower that brings humour and invention to normal perspectives. And considering the joy and unpredictability Christian Jankowski manages to extract from the dullest aspects of life, I ask myself, just how much of my own life am I mistaking for mundane?

Oobah Butler and Julie Adenuga present Catfish UK on MTV, starting in April