Carlo Acutis: How do you become a saint - and how did the millennial saint do it?

London-born teenager Carlo Acutis is about to become the first millennial saint, almost 20 years after his death.

The teenager, whose Italian family moved to Milan months after his birth in 1991, dedicated his short life to Catholicism, and died of leukaemia in 2006 aged 15.

Having passed all the posthumous trials necessary for sainthood, he will be canonised on 27 April in St Peter's Square in Vatican City.

But what does it take to become a saint and how did Carlo achieve it?

Here's everything you need to know.

What does it mean to be a saint?

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

A saint is defined in Catholicism as people in heaven who lived heroically virtuous lives, offered their life for others, or were martyred for the faith, and who are worthy of imitation.

How do you become a saint - and how did Carlo do it?

There are four steps on the path to becoming a saint:

Stage 1 - Servant of God

A postulator - essentially a cheerleader advocating for the candidate - gathers testimony and documentation and presents the case to the Vatican's Congregation for the Causes of Saints.

This process usually begins at least five years after the death of the person in question.

Carlo was dedicated to the church throughout his short life, receiving first communion at the age of seven and regularly attending daily Mass, praying the rosary and participating in eucharistic adoration.

But it was through mixing his faith with technology that Carlo had the most impact, informally becoming known as "God's influencer" as he used his computer skills to spread the Catholic faith.

He started publishing newsletters for his local churches, taking care of his parish website and later of a Vatican-based academy.

He became particularly interested in something called Eucharistic miracles.

These are events deemed miracles which take place around the Eucharist, which is the traditional name the Christian church gives to the re-enactment of the Last Supper.

It's the moment when the faithful are given a small piece of bread and a sip of wine, called the Holy Communion. They believe that, through the consumption of the bread and wine, Jesus Christ enters those who take part.

Carlo started logging miracles on a website, which eventually went viral and has since been translated into many of the world's most widely spoken languages.

Stage 2 - Venerable

If worthy, the case is forwarded to the Pope, who signs a decree confirming the candidate's "heroic virtues". The person is now called "venerable".

Carlo was named venerable in 2018 after the church recognised his virtuous life, and his body was taken to a shrine in Assisi's Santuario della Spogliazione, a major site linked to St Francis' life.

Stage 3 - Beatification

You become beatified - the declaration by the Pope that a dead person is in a state of bliss - when a miracle in your name is identified and formally declared a miracle by the Pope.

The Roman Catholic Church teaches that only God performs miracles, but that saints who are believed to be with God in heaven intercede on behalf of people who pray to them.

Typically, miracles are the medically inexplicable healing of a person.

The Pope tends to accept it as such when witnesses "verify" someone was healed after prayer and doctors/clergy conclude that it had no medical explanation, was instant and lasting.

If verified, the candidate is beatified and becomes "blessed".

Carlo's first supposed miracle was the healing of a boy called Mattheus Vianna, who was born in 2009 in Brazil with a serious birth defect that left him unable to keep food in his stomach.

As a young boy, he was forced to live on vitamins and protein shakes but regularly vomited after meals and was unable to put on weight.

Mattheus, according to his priest, touched one of Carlo's relics in church and said "stop vomiting" - an act which is said to have cured him.

In February 2014, his family ordered further tests and he was found to be fully cured, the priest said.

In 2019, the claimed miracle was acknowledged by the Vatican and confirmed by Pope Francis a few months later, paving the way for Carlo to become beatified in 2020.

Stage 4 - Sainthood

A second miracle is required in order to reach sainthood.

If verified, the candidate can be canonised and made a saint. A formal canonisation ceremony at the Vatican follows.

The second miracle in Carlo's name was the reported healing of a Costa Rican girl studying in Italy who suffered a major head trauma.

Her mother said she prayed at Carlo's tomb after the incident, invoking his spirit and leading to her daughter's full recovery.

Pope Francis attributed the second miracle to Carlo after a meeting with the head of the Vatican's saint-making department, Cardinal Marcello Semeraro, in May 2024.

Sainthood is rare - but not as much as it used to be

It isn't known exactly how many sainthoods have been handed out in the Catholic church's history, though estimates tend to sit at around 10,000.

For hundreds of years, they were selected through public acclaim, until Pope John XV led the first canonisation in the year 993, making Bishop Ulrich of Augsburg a saint.

Canonisation has been more common in recent years, though, with the late Pope John Paul II, who was the Pope from 1978 until his death in 2005, declaring 482 saints during his tenure - more than all of his predecessors.

That record was overtaken just two months into Pope Francis' tenure, as he canonised more than 800 15th-century martyrs, the so-called "Martyrs of Otranto," who were beheaded for refusing to convert to Islam.

Since then, the Pope has gone on to grant a number of other high-profile sainthoods, including his predecessors Pope John Paul II and John XXIII, married couple Louis and Zelie Martin, who lived in France during the 19th century, and Mother Teresa.

He'll take to St Peter's Square on 27 April at 9.30am UK time - in conjunction with the celebration of the Holy Year's jubilee for teens - and canonise the first ever millennial saint.

(c) Sky News 2025: Carlo Acutis: How do you become a saint - and how did the millennial saint do it?