Vice President JD Vance says he did not realize how sick Pope Francis was when he met with the pontiff at the Vatican a day before he died.

"I've thought a lot about that. I mean, it's pretty crazy, actually," Vance said. "And, obviously, when I saw him, I didn't know that he had less than 24 hours still on this earth. I think it was a great blessing."

Who will be the next pope? The decision could have a profound impact on the Catholic Church and the world's 1.4 billion baptised Roman Catholics.

It also promises to be a highly unpredictable and open process for a host of reasons.

The College of Cardinals will meet in conclave in the Sistine Chapel to debate and then vote for their preferred candidates until a single name prevails.

With 80% of the cardinals appointed by Pope Francis himself, they are not only electing a pope for the first time, but will offer a broad global perspective.

The last time the Catholic Church’s cardinals picked a pope, they wanted an outsider to overhaul a scandal-plagued Vatican. They got more of a disrupter in Pope Francis than many had bargained for.

After Francis’ stormy 12-year pontificate, some cardinals now say they want a successor who can steady the ship and defuse tensions between progressives and conservatives over divorce, same-sex relationships, priestly celibacy and other contentious issues.

It’s 10am on Sunday, and people are already starting to filter through the doors of Harbour Church. Sun streams through the windows – there’s an air of anticipation as congregation members greet each other and catch up on the week just gone. Soon, the room is filling up, the sound of gentle chatter swelling as the throng grows and people take their seats. The five-piece worship band strikes up; the crowd gets to its feet; the air vibrates as more than a hundred voices sing praises to God.

Is Christianity back? Across several countries, the last few months have seen numerous anecdotal reports of a resurgence of Christian observance. Many British clerics are noting strong attendances at Lenten and Easter services. Similar reports are emerging in the USA, where younger people make up much of the increase. Meanwhile, France has had a 50% rise in adult baptisms, and survey data suggests a fourfold increase in Catholic observance among 18 to 24-year-olds in Britain.

Sydney Johnston grew up in a nondenominational Christian household — but now the Upper West Side millennial is a devout Catholic.

“There’s just something so beautiful and transcendent about the rituals and the ancient history in the Catholic Mass that’s been preserved,” Johnston, 30, told The Post. “The church really communicates a degree of reverence that I didn’t find in the more liberal, laissez-faire approach of nondenominational churches.”

Predict who the next pope will be at your peril.

An old Italian saying warns against putting faith, or money, in any presumed front-runner ahead of the conclave, the closed-door gathering of cardinals that picks the pontiff. It cautions: "He who enters a conclave as a pope, leaves it as a cardinal".

But here are some cardinals who are being talked about as "papabili" to succeed Pope Francis, whose death at the age of 88 was announced by the Vatican on Monday. They are listed in alphabetical order...

Pope Francis’ famous exhortation to Catholic youth just months after being elected the 266th pope of the Catholic Church in March 2013 was “Hagan lio!” — “make a mess!” Twelve years later, upon his death Easter Monday morning at age 88, it’s fair to say that Francis took his own advice, making a mess of his pontificate and leaving the Catholic Church in a state of confusion and disarray.

Dust off the history books and there are papal conclaves with international intrigue, royal rigging and even riots, a checkered past that belies the air of sanctity and solemnity surrounding modern papal elections.

The word “conclave” comes from the Latin for “with key.” It is a church tradition that began in 1268 with a papal election that lasted almost three years, ending only when the townspeople of Viterbo locked up the cardinals, tore the roof off their palace, fed them nothing but bread and water and threatened them until a new pope was chosen.

In the 12 years since Cardinal Jorge Mario Bergoglio was elected Pope Francis on March 13, 2013, we’ve witnessed a rapid expansion of LGBTQ rights around the world. The pope’s death Monday is a reminder of the surprising ways his papacy was part of that wave of acceptance.