In his Mass homily, the pope said the Old Testament shows that the Ark of the Covenant in the Temple of Jerusalem was the "the symbol of the presence of God among his people."

However, "the New Testament tells us that the real Ark of the Covenant is a living concrete person -- it's the Virgin Mary," he said.

Mary offered a new dwelling place for God by carrying Jesus in her womb, showing that God no longer lives in some static location, but "lives in a person and in one's heart," he said.

The pope said Mary invites everyone today to become, "in some modest way, an ark in which the Word of God is present" and has transformed and enlivened one's life.

A few hours after the Mass, Pope Benedict led the recitation of the Angelus prayer with visitors gathered in the courtyard of the villa.

He continued reflecting on Mary's life and her assumption into heaven. He said that Mary was taken, body and soul, into heaven is "a great mystery," which brings hope and joy to all those who believe.

"In Mary we see the destination toward which walk all those who know to link their own life to Jesus' life, who know to follow him as did Mary," he said.

The feast of the Assumption is about the future of every Christian -- living in eternal life next to Jesus in God's glory, he said.

He told pilgrims to have courage and believe that the power of Christ's resurrection can be at work in every person so that they can bring the light of goodness to the darkness of the world.

The pope also recited the Angelus prayer at noon Aug. 14 at the papal villa. Many of the visitors in the courtyard were young people en route to World Youth Day in Madrid.

He asked everyone "to accompany us with your prayers for the spiritual fruitfulness of this important event" in the Spanish capital. The pope was to attend events Aug. 18-21.

The pope also greeted pilgrims from Cuba. Cardinal Jaime Ortega Alamino of Havana was "leading the first pilgrimage for Cubans to the tombs of the Apostles" in Rome, the pope said.