Pope Francis says Catholics must have faith against adversity as he marked Easter Sunday with an open-air mass to be followed by the Urbi et Orbi (To the City and to the World) message and blessing.
"In this land of pain, of tragedies, amid so many calamities, the faith in the resurrected Christ gives us a meaning, [it allows us] to look beyond," the Pope told crowds in St Peter's Square, which was decorated with some 35,000 flowers and plants from the Netherlands.
Dozens of cardinals and bishops and other high-ranking prelates were in attendance, along with tens of thousands of faithful, who were subjected to security screenings due to terrorism concerns.
Watch: Easter celebrations around the world
In unscripted remarks, the Pope said he had a phone conversation with a sick man on Saturday and told him there was "no explanation" for his illness, but reminded him that even Jesus Christ had to suffer crucifixion.
"Nobody asks us: Are you happy about what happens in the world? Are you prepared to carry this cross?" the pontiff said.
Easter is "more than a party with many flowers," Francis said, ending his speech with the entreaty, "As you go home today, repeat to yourselves: Christ has resurrected."
As he finished his unscripted homily, heavy rain started.
After Mass, the Pope toured St Peter's Square with the popemobile to greet the faithful, and then was due to deliver the Urbi et Orbi message - usually a call for world peace - from the central balcony of St Peter's Basilica.
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Catholics celebrate Easter on the Sunday that follows the first full moon after March 21. For the Orthodox, who use the Julian rather than Gregorian calendar, it often falls a week later.
Several rituals punctuated the Catholic run-up to Easter, including Holy Thursday's foot-washing ceremony, which Francis this year performed in a prison for Mafia turncoats south-east of Rome.
On Friday, the pontiff led the Via Crucis (Way of the Cross) procession at the Colosseum. On the eve of Easter, Francis celebrated the traditional Vigil Mass in St Peter's Basilica.
Sunday also marks the 90th birthday of Francis' predecessor, Pope Emeritus Benedict XVI. He is the only Catholic Church leader in almost 600 years to have quit while in office, rather than serving as pope until death.
