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.