* Pope says 'authentic' values important in modern society
* Mass at aerodrome highlight of World Youth Day festival
* Several injured in Saturday storms during prayer vigil
* Protests continue over papal visit
By Judy MacInnes and Sonya Dowsett
MADRID, Aug 21 (Reuters) - Pope Benedict urged 1.5 million
young Catholics at a Sunday mass in an aerodrome near Madrid to
spread the gospel to others seeking better values than modern
"We cannot encounter Christ and not want to make him know to
others. So do not keep Christ to yourselves! Share with others
the joy of your faith," he said in a sermon as part of the
activities of the Roman Catholic Church's World Youth Day.
The pope, closing a four-day trip to Spain which has been
marked by protests, told pilgrims from around 190 countries that
they have been given "the extraordinary task" of being
missionaries of Christ in other countries filled with young
people looking for better values.
"And, because their heart tells them that more authentic
values do exist, they do not let themselves be seduced by the
empty promises of a lifestyle which has no room for God."
Hundreds of thousands of young people, bearing flags from
their countries and wearing hats to protect themselves from the
sun, prayed, applauded and cheered during the service.
The pope read his sermon seated on a white throne under a
stylised golden tree, with Spain's King Juan Carlos and Queen
Sofia looking on. A choir and orchestra dressed in blue and
adorned with white lilies accompanied the mass.
Benedict led a prayer vigil at the Cuatro Vientos aerodrome
on Saturday evening, but heavy rain prevented him from reading a
prepared speech in which he had made a veiled criticism of
Spain's legalisation of gay marriages and abortion.
An electric storm followed a day of sweltering heat in
Madrid, and wind during the night damaged tents, injuring seven
people, emergency services said.
Emergency services helped more than 1,500 young people
during Saturday's vigil, most with heat-related complaints.
But hundreds of thousands again packed the aerodrome on
Sunday to join the Mass, the highlight of the WYD jamboree.
"When you're at home you just think you're alone in your
faith, but when you pray with over a million people it just
changes things," said Katharina Eisen, 18, from Germany.
For an Interactive timeline on recent Papal visits please
click on http://link.reuters.com/vud33s
For a FACTBOX on Catholicism in Spain
For at TIMELINE on Benedict as Pope
The cost of the pope's trip to Madrid has angered some
Spaniards struggling with recession and high unemployment. Heavy
security has surrounded the pontiff, with roads cut off to
traffic and thousands of police on the streets.
World Youth Day organisers say the pope's visit costs the
taxpayer nothing. Critics have put the cost at about 100 million
euros, mainly in security expenses.
Benedict's trip has reignited criticism by Los Indignados
(The Indignant Ones), a group whose mainly young members
occupied Madrid's Puerta del Sol square in May to protest
against high unemployment and government spending cuts.
(Reporting by Judy MacInnes and Sonya Dowsett; additional
reporting by Brenton Cordeiro; editing by Alistair Lyon)
© 2015 Thomson/Reuters. All rights reserved.