Pope Francis is to celebrate his first Easter vigil after praying for peace in the Middle East and stronger Christian-Muslim dialogue at a torch-lit ceremony for Good Friday.
The newly elected Argentine pope will preside over a mass at St Peter's Basilica from 1930 GMT, baptising four adult converts - an Albanian, an Italian, a Russian and a US national.
The ceremony will wrap up a series of intensive preparations leading up to Easter Sunday - the holiest day in the Christian calendar - by the first non-European pope in nearly 1,300 years.
Tens of thousands of people are expected at mass on Sunday when the pope will issue a special blessing from the same balcony of St Peter's Basilica where he appeared on the night of his election.
In only the second time in history, a 30-minute showing of the Holy Shroud - which according to Catholic tradition wrapped the crucified body of Christ - was broadcast live on Saturday afternoon by Italian public channel Rai Uno to mark the celebrations. The first time it was broadcast was in November in 1973.
"The face of the shroud communicates great peace," the pope said in a video-recorded message ahead of the exhibition. "It is as if he is saying: 'have confidence, do not lose hope, the power of God's love, the force of the resurrected, conquers all'."
Giovanni Maria Vian, editor of the Vatican's official daily Osservatore Romano, said seeing the new pope during Easter helped explain the timing of his predecessor Benedict XVI's resignation.
"Thanks to the timing chosen for this decision, his successor has managed to make the start of his service as successor of St Peter coincide with this most important celebration," he wrote.
"It is in these crucial liturgical days that we have heard the strength of the voice of a pope who has come for the first time almost from 'the ends of the world' as he himself said," Vian wrote.
"In all his life as priest and bishop he has always shown a special concern for material and spiritual peripheries," he said, underlining the pope's Holy Week message of bringing the troubled Roman Catholic Church closer to the needy.
Francis marked Good Friday with a traditional ceremony at the Colosseum in Rome, presiding over the re-enactment of Jesus Christ's last hours.
'Respond to evil with good'
"Christians must respond to evil with good, taking the cross upon themselves as Jesus did," said Francis, who followed the ceremony from under a canopy overlooking the 2,000-year-old Roman amphitheatre.
The pope also referred to a visit to Lebanon last year by Benedict, who stunned the world by resigning last month at the age of 85 saying he was too weak mentally and physically to continue.
"We saw the beauty and the strong bond of communion joining Christians together in that land and the friendship of our Muslim brothers and so many others," the 76-year-old pope said.
In Jerusalem, tens of thousands of pilgrims packed into the Old City for Good Friday - and in the Philippines Catholic zealots had themselves nailed to crosses in a grisly Easter ritual that persists despite Church disapproval.
At the Colosseum ceremony in Rome, prayers read out were written by a group of Lebanese young people who voiced hope for a Middle East "torn apart by injustice and conflicts".
The Vatican has voiced concern over the fate of Christian minorities in many parts of the Middle East and the rise of radical Islam, as well as calling for an end to conflict in the region.
Francis began the Easter season on Holy Thursday by washing the feet of 12 young prisoners including two Muslim inmates in an unprecedented new take on an ancient pre-Easter ritual.
Popes performing the ceremony - which commemorates the gesture of humility believed to have been carried out by Jesus for his 12 disciples - have usually washed the feet of priests.
Francis's trip to the Casal del Marmo youth prison was the first time a pontiff had performed the act in a jail, and the first time women and Muslims were included.
Latin America's first pontiff has set a markedly different tone from his predecessor, with a more informal style that is unusual in the Vatican halls of power.
He was known in his native Argentina for his humble lifestyle, his outreach in poor neighbourhoods and his strong social advocacy during his homeland's devastating economic crisis.
Vatican experts say he is yet to begin tackling the many problems assailing the Church, however, including reform of the scandal-ridden Vatican bureaucracy and bank.