Carlo Acutis, a teenager of British and Italian descent who passed away in 2006, is set to be canonised by Pope Leo on Sunday, marking him as the first millennial saint in the Catholic Church. 

The ceremony will take place in St Peter’s Square at the Vatican and will be attended by thousands of pilgrims. 

After fulfilling all the necessary posthumous criteria for sainthood, his canonisation was initially planned for April, but the ceremony was delayed following the death of Pope Francis. 

It was Francis who had willed Acutis’ sainthood forward as he believed the church needed someone like him to attract young Catholics to church. 

But what does it take to be raised to sainthood and how did Acutis achieve it? 

In Catholicism, saints are individuals believed to be in heaven who led virtuous lives and had a profound connection with God, using their faith to assist others.

All Christians are called to be saints, but only a select few have been officially recognised as one throughout history. 

These are the five steps on the path to becoming a saint.

Step One: Five-Year Wait 

The process to make someone a saint cannot start until at least five years after their death.

This allows for a period of reflection to ensure that the person’s case can be evaluated objectively. 

However, the waiting period can be waived by the Pope. 

Acutis, who was born in London in 1991 to an an Italian mother and a half-English, half-Italian father, had an ardent faith, though his parents were not particularly devout.

He grew up in the northern city of Milan, where he attended mass daily and had a reputation for kindness to bullied children and homeless people, bringing the latter food and sleeping bags.

In Milan, he took care of his parish website and later that of a Vatican-based academy.

A fan of computer games, Acutis taught himself basic coding and used it to document miracles and other elements of the Catholic faith online.

After being diagnosed with Leukemia in October 2006, he told his parents: ‘I’m happy to die because I’ve lived my life without wasting even a minute of it doing things that wouldn’t have pleased God.’

Step Two: Servant of God 

Once the five years are up, the bishop of the diocese where the person died can open an investigation into the life of the individual and has to investigate whether their life was holy enough to be deemed a ‘servant of God’.

If there is sufficient evidence, the bishop asks the congregation for the Causes of Saints – a department that advises the Pope on saints – for permission to open the case and to call the individual a ‘servant of God’. 

Step Three: Life of Heroic Virtue 

The Congregation for the Causes of Saints then looks at the case. If they approve it is passed onto the Pope, who declares the individual a person of ‘heroic virtue’. 

After this stage, the individual can then be called ‘venerable’. 

Step Four: Beatification

To reach the next stage of beatification, a miracle needs to happen to a person who has prayed to the person in question.

The Vatican has recognised Acutis as performing two miracles himself since his death – a necessary step on the path to sainthood.

The first was the healing of a Brazilian child called Mattheus Vianna suffering from a rare pancreatic malformation in 2009.

As a young boy, Mattheus lived on vitamins and protein shakes, but regularly vomited his meals and struggled to put on weight. 

According to his priest, Mattheus touched one of Acutis’ relics in church and said ‘stop vomiting’ – an act which is said to have cured him. 

The miracle was confirmed by Pope Francis in 2019.

Step Five: Canonisation

A second miracle is attributed to the person who has been beatified.

If verified, the individual can be canonised.  

The second miracle in Acutis’ name was the recovery of a Costa Rican girl who was  seriously injured in an accident.

Her mother claims to have prayed to Acutis’ tomb after the accident, which she says later led to her daughter’s full recovery. 

Pope Francis confirmed the miracle in May 2024, shortly before his death.   

 Acutis’ embalmed body, dressed in jeans and a pair of Nike trainers, lies in a glass-walled tomb in Assisi, visited by hundreds of thousands of people a year.

His canonisation will be watched by faithful on giant screens in Assisi, a medieval city and pilgrimage site in the central region of Umbria.  

Italian Pier Giorgio Frassati, a mountaineering enthusiast who died in 1925 and was known for his social and spiritual commitment, will also be made a saint on Sunday.

His casket is inscribed with the words ‘Verso l’alto’ (‘To the heights’), a phrase he wrote on a photograph taken of him looking up to the summit while mountaineering.

An engineering student who made it his mission to serve the poor and sick of his city, he was held up by the Church as a model of charity after his death of polio aged 24.

He was beatified by John Paul II in 1990.

Sunday’s canonisation ceremony will be Pope Leo XIV’s first since his election in May.

It falls during the Jubilee, a Catholic ‘Holy Year’ which has already drawn over 24 million people to Rome, according to the Vatican.