Pope John Paul II is to preparing to celebrate his annual Easter vigil Mass Saturday, at Saint Peter's Basilica, one day after presiding over a solemn service at Rome's ancient Coliseum on Good Friday.

Amid exceptionally tight security, the pope Friday led thousands of Roman Catholics in prayer at the ancient stadium where early Christians were first persecuted nearly 2,000 years ago.

John Paul presided over The Stations of the Cross procession also known as "Via Crucis", which symbolically traces Jesus' path to his crucifixion. He said the suffering of Jesus, after 20 centuries, continues to move Catholics.

On Sunday, Pope John Paul will deliver his traditional blessing and message "Urbi et Orbi," which in Latin means "to the city and the world."

The 83-year-old pontiff spoke in a relatively clear voice Friday despite concerns about his health. He suffers from the neurological illness, Parkinson's Disease, as well as arthritis and other ailments.

Roman Catholics and other Christians who use the Julian calendar, and Orthodox congregations who use the Gregorian calendar are all celebrating Easter this year on April 11.

Christians believe Jesus is the son of God, and that he rose from the dead on Easter Sunday after his death by crucifixion to save the world from sin.