I came face-to-face with the Nike-wearing saint

Unless you have looked at a picture to prepare yourself, at first sight the tomb of the Blessed Carlo Acutis , which stands in the Church of Santa Maria Maggiore in the Umbrian hill town of Assisi , would strike you as distinctly unusual, perhaps a little unsettling.

There, in a glass-sided tomb, lies the body of a teenage boy wearing jeans, a track top and a pair of Nike trainers , a rosary clutched in his hands. The way the body is presented, it seems as if he is floating.

His face, fixed in an expression of benign repose, is actually a silicone mask. It looks uncannily real, as though he is not dead, but simply sleeping. It is like a piece of holy conceptual art.

Beside the tomb is a photograph of a smiling Carlo, the ordinary teenager, very much alive, dressed in jeans and a zip-up jacket, rucksack on his shoulder.

Acutis, who died in 2006 at the age of 15 from leukaemia , has been popularly referred to as God's influencer and the first millennial saint. In order for someone to be recognised as a saint, there must be two miracles attributable to his or her intercession. In the case of Acutis these came in the form of the healing of a four-year-old boy in Brazil, and a 21-year-old woman from Costa Rica, more on which later. Both have been 'approved' by the Vatican .

The final step to him becoming Saint Carlo will be the canonisation Mass, which will likely take place next year, a Jubilee year for the Catholic faith, when hundreds of thousands of people from all over the world are expected to descend on Rome and St Peter's Square.

"I would say, at this time, he's probably the most popular saint in the world," says Monsignor Anthony Figueiredo, as we stand in the square outside the Church of Santa Maria Maggiore. "It's a big statement, but I see it, I know it."

Figueiredo, 60, is a former City trader who was ordained as a priest in 1994, and worked in the Vatican before being sent to Assisi in 2020 as director of international affairs for the diocese – a role that largely means dealing with what he calls "the phenomenon" of Carlo Acutis.

As we talk, groups of pilgrims arrive, distinguished by blue scarves or white caps. A troop of Italian cubs wait in line. Two Slovenian monks in brown robes are shepherding a group of teenagers who are sitting in a small garden beside the church, singing songs to the accompaniment of a guitar. Over a six-month period last year, Figueiredo says, the church counted more than 500,000 people visiting the tomb, and numbers have only increased since then.

Images of the youthful Acutis have been reproduced countless times on posters, prayer cards, in the form of statues, and circulated on social media. On TikTok, one account dedicated to him has more than 700,000 likes. Courtney Mares, the author of a biography called Blessed Carlo Acutis: A Saint in Sneakers, describes him as "the first saint of the internet age". "Carlo is the first to be put forward by the Vatican showing what holiness can look like in our digital age ," she says.

"And I think that's one of the ways he is resonating around the world. The fact that he lived a relatively normal life as a teenager and yet he's now being declared a saint shows us that holiness is possible in the 21st century in our daily lives."

It's a reasonable question. How, in the 21st century, does a 15-year-old boy become a saint?

To all outward appearances, there is nothing in the story of Carlo Acutis's short life that would have pointed to his elevation to sainthood. Home videos and photos show a normal, happy boy, pulling faces at the camera, diving into a river, petting his dogs. Nothing unusual there.

His father Andrea was a merchant banker, and is now chairman of Vittoria Assicurazioni SpA, one of Italy's largest insurance companies. The family were living in London when Carlo, their first child, was born on 3 May, 1991. He was baptised in a church in Fulham, where a shrine to him now stands.

A few months after his birth they returned to Italy, settling in an apartment in an affluent quarter of Milan. The family were not practising Catholics . But when he was three they hired a Polish nanny, a devout Catholic, who would take Carlo to Mass and taught him to recite the Rosary.

From that point on, he showed a particular devotion to the Church and to prayer. At the age of seven, at his request, his parents arranged for him to receive his first Communion, held in a private ceremony at a cloistered convent. The religious superior of the community later spoke of how as the moment for the Communion approached, he "began to move as if he could no longer keep still. It seemed that something had happened within him, something too great for him to contain."

"Being always united with Jesus," he wrote when he was seven years old, "this is my life plan."

A school friend, Federico Oldani, remembers him as "a real person. He was someone who got angry if his homework went badly, someone who the French teacher always scolded because he made a mess, who was late for school even if he lived two metres away. But the more you got to know him, the more you realised he was special."

The various accounts of his life tell of how he would take food and drink to the homeless and buy sleeping bags for them with money he'd saved. Classmates who were being bullied or shunned have said that he would step in to help and support them.

Taken individually these acts seem praiseworthy, but not especially remarkable. Taken together with other stories they paint a picture of an unusually pious teenager.

It has become a key part of Acutis's story that such was his religious devotion, his mother came to renew her Catholic faith. Rajesh Mohur, who was employed by the family as an au pair and would also take him regularly to Mass, has told how, inspired by Acutis, both he and his mother, who had been Hindus, converted to Catholicism.

Acutis would often talk to his schoolmates too about the importance of going to Mass and confession. His views were strictly in line with traditional Catholic teachings. He was against abortion , and while the object of a number of crushes, he remained chaste, telling his family that the Virgin Mary was "the only woman in my life".

"He would have conversations with some of his friends about the importance of chastity among high-school kids," Courtney Mares says. "I don't know if that would normally make him the most popular kid in school, but he wasn't afraid to stand up for what he believed in... and his friends and classmates really loved and respected him."

Acutis was given his first computer when he was nine and was soon learning to code from textbooks bought by his mother. Like any boy of his age, he enjoyed video games, but according to his mother he would limit his game time to one hour a week.

Following his death, his computer was examined and, perhaps uniquely for a teenage boy, there was no evidence of him ever having visited "immoral" sites, as Monsignor Figueiredo puts it.

At the age of 14 he was creating a website for his local parish and had started compiling what would become his unique legacy – a history of more than 100 supposed miracles to do with the Eucharist, the ceremony commemorating the Last Supper, in which bread and wine are consumed, and at which, according to the supposed miracles, the bread and wine are said to have actually turned into flesh and blood. The earliest of these is said to have taken place in 750 in Lanciano, Italy; the most recent in 2013, in Legnica, Poland. Acutis's historical account would subsequently be posted on a website, The Eucharistic Miracles of the World, and turned into an exhibition.

On 2 October, 2006, Acutis complained of a headache, and fell ill with a fever, which quickly worsened. He was taken to a clinic where he was diagnosed as suffering from acute promyelocytic leukaemia, a form of cancer often linked to early death due to bleeding complications associated with the disease. He'd had no previous symptoms or serious illnesses.

He was transferred to a hospital in Monza, where he died on 12 October.

His mother would subsequently talk of how during the five days it took him to die, "he was always smiling, never complaining and saying there are people who are suffering much more than I.

"When we went in the hospital he said, "Mama, from here I never will come back alive, but don't worry, I will give you a lot of signs." And since the first day after the funeral he started to give miracles."

Saint-making is a process of tortuous complexity. Under canon law, five years must pass between a candidate's death and the first step towards beatification, on the path to canonisation. (There have been exceptions, with shorter waiting periods in the cases of Mother Teresa and Pope John Paul II.)

At that point, the bishop of the diocese in which the individual died can petition the Holy See to initiate the cause, as it is called. A postulator, or promoter, is appointed to gather testimony from a wide range of people who have known the candidate, and evidence demonstrating that they have led a life embodying the Christian virtues of humility, simplicity and service to others.

It must also be demonstrated that they have been responsible for at least one miracle since their death, which the Vatican describes as an intervention of God that goes above and beyond the laws of nature – usually a cure deemed to be "scientifically inexplicable". A second miracle is required after beatification before the person can be canonised .

This body of evidence, or positio, usually of more than 1,000 pages, is passed to the Vatican's Dicastery for the Causes of Saints. This body, which has been examining causes of saints since the 16th century, has among its prelates a "promoter of the faith" – the so-called "devil's advocate" – who acts as a sort of counsel for the prosecution, interrogating the evidence and presenting any arguments against the beatification. That position is currently held by a Spanish priest, Monsignor Alberto Royo Mejía.

"It's essential that someone help search for the truth," he told the Catholic news agency ACI Prensa in an interview this year, adding that "all people have defects; there is no saint who does not have any defects".

A Vatican medical board evaluates the evidence for each claimed miracle. The submission is then passed to the Pope to "pray to God for guidance" and give his final approval.

"We didn't know Carlo was a saint during his life," Monsignor Figueiredo says. "He didn't do anything extraordinary – he didn't build an institute or found a new religious order. He didn't have people following him.

"When we knew there was something different about him was at his funeral; there were so many people, they were spilling out into the streets. His parents didn't know who these people were. And they were the beggars, the immigrants, the kids who'd been bullied – people Carlo had befriended and helped in his life. That was the point when the question arose, how did he touch so many people's lives?"

As word started to spread about his life a cult began to form – not a word that in Catholic terms has negative connotations.

Sainthood, says John Allen, an author and authority on the Vatican who edits the Catholic news website Crux, "is supposed to be the most grassroots process in the Catholic Church. It's not supposed to be top-down, it's supposed to be bottom-up. And there was a popular interest in Carlo Acutis well before officialdom stepped in."

A website dedicated to his life was set up by the Friends of Carlo Acutis Association. Stories began to appear in newspapers, and Nicola Gori, a journalist for the Vatican newspaper, L'Osservatore Romano, published a book about Acutis, Eucaristia: La mia autostrada per il cielo (The Eucharist: My Highway to Heaven). It was Gori who became the postulator of the cause.

"Even before anything had happened formally, people were going to the cemetery in Assisi to pray to Carlo," Figueiredo says. "The mayor of Assisi talks about being taken by her grandmother. So he already had that kind of fame – what we call the odour of sanctity."

On the sixth anniversary of his death, the Archdiocese of Milan duly opened the cause for Acutis's beatification, leading to him being formally given the title "servant of God". As momentum grew, on 5 July, 2018, Acutis was declared "venerable" by Pope Francis, a declaration of having lived a life that was "heroic in virtue" in the eyes of the Church, and a step towards beatification.

Driven, appropriately enough, by the internet, stories multiplied of laypeople and priests inspired to pray to him.

What was now required was a miracle.

It came from Brazil, where a priest in Campo Grande, Father Marcelo Tenório, had first learned of Acutis in 2010 and established a shrine to him, including a relic – a piece of his clothing – given to Tenório by Carlo's mother on a visit to Assisi. Each year, on 12 October, the anniversary of Acutis's death and the feast day of Our Lady of Aparecida (the patron saint of Brazil), Tenório would conduct a special service displaying the relic for people to pray for Acutis's intercession for whatever healing they might need.

A member of the congregation, Luciana Vianna, had a four-year-old son, Matheus, suffering from a serious condition called annular pancreas. Unable to eat properly or hold down food, he was living on vitamin and protein drinks and weighed only 20lb, making him too weak for surgery. Doctors told Vianna her son would die before he was five.

On 12 October, 2013, Vianna took Matheus to the church. In an interview with the Catholic publication America, she would later recount how he was carried to the shrine, leaned forward to kiss the reliquary containing the piece of clothing and – in a moment witnessed by many other people – said out loud, "Stop vomiting."

According to his mother, Matheus was unusually joyful – and hungry – following the service, and on returning home ate beef and French fries without becoming sick.

"It was the first time in his entire life that this happened. He had been vomiting after eating since he was born; he even rejected breast milk," she said. "Since that day, I knew he was cured because of Carlo. The change was too drastic and too sudden."

Subsequent medical tests showed his condition had been cured. "One doctor said that he then had a textbook pancreas, an organ that is so perfect that it looks unreal."

In an interview with a Brazilian television station in 2020, Dr Rosângela Maria Pereira Salgado, who had been Matheus's paediatrician since his birth, said his healing could not be explained. "He could only be cured through surgery. The previous exam [before the miracle] showed the malformation. The following one [after the miracle] didn't show the malformation any more. Science doesn't explain that."

After Matheus's health records had been validated by local doctors, they were passed to the Dicastery for the Causes of Saints to be evaluated by what the Vatican stipulates to be "highly specialised medical experts". In November 2019, the healing through the intercession of Carlo Acutis was formally confirmed by the Vatican.

"A secularist would say it's just random luck this boy was healed," says John Allen. "But from a Catholic point of view, if you have somebody who went to church, prayed to this figure to intercede before God that their son can be healed, and medical doctors sign off saying there is no medical explanation, then from a faith point of view that is going to be attributed to the saint's intercession."

(What cannot be known, of course, is how many people have prayed to Carlo Acutis for healings that have never come, or may have come but have never been attributed to him. The imponderables are countless.)

In October 2020 Acutis was duly beatified at a ceremony in Assisi, and officially declared as "blessed". Thousands of people processed past the tomb and a live-stream posted on social media spread it around the world.

As Courtney Mares puts it, "That's when he really went viral."

Canonisation does not always immediately follow beatification. In some cases it can take centuries. The Argentinian laywoman María Antonia de San José de Paz y Figueroa, known as "Mama Antula", who was canonised in February of this year, died in 1799. "Most saints," Figueiredo says, "wait hundreds of years to get on to the ticket." In many cases, canonisation doesn't happen at all.

But the second miracle necessary for Carlo Acutis to complete the path to sainthood followed with uncommon alacrity.

On 2 July, 2022, a 21-year-old woman from Costa Rica called Valeria Valverde, who was studying fashion in Florence, was involved in a bicycle accident, seriously injuring her head. According to the Dicastery for the Causes of Saints, following an emergency craniotomy to reduce intracranial pressure, her family was told that her situation was critical and that she could die at any moment.

Valverde's mother went to Assisi to pray for her daughter at the tomb of Carlo Acutis. That day, she began to breathe independently; the next day she regained the use of her upper limbs. She was discharged from intensive care 10 days later, and further tests showed that the haemorrhagic right temporal cortical contusion in her brain had vanished.

Two months to the day after her accident, she and her mother went on a pilgrimage to Acutis's tomb, to celebrate her complete healing.

In a decree on 23 May, 2024, Pope Francis approved the healing as a miracle.

The speed at which Carlo Acutis has progressed on the path to sainthood has raised questions in some Catholic circles about both his elevation, and the process of saint-making in general.

Pope John Paul II, who died in 2005, was a prolific maker of saints, beatifying and canonising more people than all his predecessors combined. Pope Francis has been even more prolific, canonising 912 saints during his 11 years as Pope – although this does include the 813 Italian "martyrs of Otranto", who were massacred in 1480 by the Turks and canonised en masse in 2013.

At a time when church attendances are falling, particularly among the young, the emergence of a teenage saint could be seen, for want of a better word, as a godsend.

"There is a feeling that under Pope John Paul II and Pope Francis it may be considerably faster to become a saint and that the Catholic canon of sainthood is being somewhat watered down by the addition of too many potential saints," says William Cash, editor of the Catholic Herald. "This is something that some Catholics feel a little uneasy with.

"I'm sure Pope Francis is keen to engage younger Catholics and have a digital saint. I can see that totally makes sense."

He continues: "Nothing I have seen, heard or read suggests that Carlo was not an extremely holy person who deserves to be recognised. But the question some Catholics ask is, has this process of beatification under Francis introduced a different bar than in previous centuries?"

"Every sainthood process is one part holiness and one part politics," John Allen says. "The declaration of sainthood is not for the saint, it's for the rest of us. It's a way of saying, you should follow this person's example. And inevitably there is politics involved in that. A young layperson who was not a candidate for the priesthood but nevertheless was devoted to the Eucharist and was strongly pro-life – from the Catholic point of view that's like the golden ticket."

The process of making a saint is not cheap. US Catholic officials have previously cited $250,000 as a benchmark for the cost of a cause, from the initial investigation on a diocesan level, to a canonisation Mass in St Peter's Square at the Vatican, although that cost can increase depending on the numbers of people taking part. The bulk of the cost is usually met by the diocese.

"Carlo has been fast-tracked," Monsignor Figueiredo says. "And there has been some controversy about that, the parents being wealthy. Even here in Assisi some people say they probably bought this, which is ridiculous. You don't buy a sainthood."

That debate aside, the benefit to the Catholic Church has been undeniable. "He's certainly been marketed brilliantly," one visitor at the tomb in Assisi told me. It was a professional opinion – he was from Glasgow and ran a marketing company. I sensed a degree of scepticism. But not at all. He believed without a shadow of a doubt, he said, that Acutis was a true saint.

The most energetic promoter of the cause of Carlo Acutis has been his mother, Antonia. When, at the age of 44, she gave birth to twins, Michele and Francesca, four years to the day after Carlo's death, she suggested their birth had been the result of divine intercession. A year after his beatification, she published a book, Il segreto di mio figlio: Perché Carlo Acutis è considerato un santo (The Secret of My Son: Why Carlo Acutis Is Considered a Saint).

Last year, she was in London, giving talks. The Catholic journalist Melanie McDonagh attended one of them, at Corpus Christi, Maiden Lane. The church, she remembers, was packed beyond capacity.

McDonagh was sceptical about the cult of popularity around Acutis – "the kind of saint you'd want if you wanted to appeal to a young demographic". But hearing his mother speak about him changed her mind.

"I was very impressed. She was very composed and spoke with great simplicity, not at all mawkish and sentimental. It could have seemed dreadful but it wasn't. I said to her, "You must miss him." She said, "Yes, but life is short." For her there will be a reunion.

"What Carlo represents is not reformist in any way. It's very traditional – the Rosary, the Eucharist. And it's very interesting that a teenager should appeal on that level."

In the course of his life, Carlo Acutis spoke of feeling a particular love for St Francis of Assisi as an exemplar of the Christian way of life, and a particular connection to the beautiful little medieval town – a place of twisting streets and alleyways, and the constant peal of bells from its numerous churches – where St Francis lived and died. The family would visit so often for holidays that they bought a house there.

Immediately following his death, Acutis was buried in Ternengo, in the Italian region of Piedmont. But in January 2007 his body was transferred to the cemetery in Assisi, and in January 2019, following his recognition by Pope Francis as venerable, his body was exhumed and moved to the Church of Santa Maria Maggiore, where it now rests.

There is a long history of the "incorruptible bodies" of saints in the Catholic Church – bodies that appear to have completely or partially avoided decomposition as a result, it is said, of divine intervention. There are 102 saints or "blesseds" whose bodies are recognised by the Church to be incorrupt.

When Acutis's body was first put on display, the rumour spread that his body too was incorrupt – it certainly looked it – obliging Domenico Sorrentino, Bishop of Assisi, to clarify that at the time of his exhumation the body, though intact, "was found in the normal state of transformation typical of the cadaveric condition".

There are, however, a number of relics – the physical remains or personal possessions of a saint, which are preserved for the purpose of veneration. The most valued of these – so-called first-class relics – are pieces of the body of the saint. In the case of Carlo Acutis, there are four pieces of his pericardium, the membrane that encloses the heart and the beginnings of the great blood vessels, contained in reliquaries. Figueiredo is responsible for one of them, fulfilling requests from various dioceses to display the relic for veneration. It has been displayed in churches in Italy, Ireland, the US and the UK.

The most common "first-class" relic is a piece of Acutis's hair. "I don't know the exact number now, but I would say it's well over a thousand," Figueiredo says. "Carlo had a great head of hair."

One such relic is to be found at Our Lady of Dolours on Fulham Road in London, where he was baptised. The church also has other relics, including a piece of bone from the 14th-century saint Peregrine, the patron saint of those suffering from cancer.

Each Monday the reliquary containing strands of Acutis's hair is placed on the altar when there are special prayers for his intercession. The service is often attended by families visiting patients in the nearby hospital.

"Some people want to touch the glass, or kiss the glass, and we have a piece of tissue or cloth so they can do that," one of the church's priests, Father Chris O'Brien, told me. "There's something about touching. Everybody wants to touch everything." He paused. "It was a nightmare during Covid."

"We Catholics are very odd," Xavier Galves told me with a smile. I met him at the tomb of the Blessed Carlo, where I had been standing for the best part of an hour, watching as people moved past, kneeling, praying, touching...

He was an architect, visiting Assisi from Mexico City with his family, pilgrims to the tombs of St Francis and Carlo Acutis. We talked about miracles. "The miracles that are done by Carlo or any other saint are done by God," he insisted. "It's not as if he was just made a saint by the Church – there has to be a whole process behind it." He laughed. "We can't be worshipping false idols."

His daughter Maria Lourdes had been kneeling at the tomb, and walked over to join us, looking visibly moved. She was 20, studying multimedia design. She had first heard about Acutis at school, she said, when a friend who had been to Assisi brought back a picture of the tomb. I asked her, what did it mean to see it for herself?

"I guess it means hope, a hope that you can do great things in ordinary life and make ordinary life extraordinary." She paused, wiping her eyes. "Seeing him with a jacket I could wear, seeing his face so young – all those little things connect you [to the fact] that sainthood isn't just for a St Francis or St Clare. I can't wear a sackcloth and move to the centre of Italy..." she smiled. "But I have a pair of Nikes."