The Shroud of Turin has gone on display for a special television appearance in Italy, as new research disputes claims that the linen is a medieval fake.
Pope Francis sent a video message to the event at Turin's cathedral, but made no claim that the image on the shroud of a man with wounds similar to those suffered by Christ was really that of Jesus.
Many experts stand by carbon-dating of scraps of the cloth that date it to the 13th or 14th century.
However, some have suggested the dating results might have been skewed by contamination and have called for a larger sample to be analysed.
New research purports to date the linen - which some say was Jesus Christ's burial cloth - to around the time of his death.
The Vatican has tiptoed around just what the cloth is, calling it a powerful symbol of Christ's suffering while making no claim to its authenticity.
"This disfigured face resembles all those faces of men and women marred by a life which does not respect their dignity, by war and violence which afflict the weakest," Pope Francis said in his video address.
"The face in the shroud conveys a great peace. This tortured body expresses a sovereign majesty.
"It lets a pure and calm energy shine through and it seems to say to us: 'Trust and don't to lose hope. The power of the Lord defeats all'."
The 14-foot-long and 3.5-foot-wide cloth is kept in a bullet-proof, climate-controlled case in Turin's cathedral, but is only rarely open to the public.
The last time was in 2010 when more than two million people lined up to pray before the shroud.
The latest display coincided with Holy Saturday, when Catholics mark the period between - according to Christian faith - Jesus's crucifixion on Good Friday and his resurrection on Easter Sunday.
The display also coincided with the release of a book based on new scientific tests on the shroud that researchers say date the cloth to the 1st century.
The research in The Mystery Of The Shroud, by Giulio Fanti of the University of Padua, and journalist Saverio Gaeta, is based on chemical and mechanical tests on fibres of material extracted for the carbon-dating research.