Pope Francis attributed two miracles to Carlo Acutis and so the test was passed and he was due to be made a saint on 27 April.
But Pope Francis died during the preceding week.
Some followers who had travelled to Rome for the canonisation instead found themselves among the tens of thousands of mourners at the late pontiff’s funeral – Diego Sarkissian, a young Catholic from London, was one of them.
He says he feels a connection to Carlo Acutis and is excited by his canonisation.
“He used to play Super Mario video games on the old Nintendo consoles and I’ve always loved video games,” Mr Sarkissian says.
“The fact that you can think of a saint doing the same things [as you], wearing jeans, it feels so much closer than what other saints have felt like in the past,” he says.
Approval for someone to become a saint can take decades or even centuries, but there is a sense that the Vatican fast-tracked Carlo Acutis’ canonisation as a means of energising and inspiring faith in young people.
The Catholic Church will be hoping Sunday’s events do just that.