VATICAN CITY — Pope Francis celebrated his first Palm Sunday Mass in St. Peter’s Square, encouraging people to be humble and young at heart and promising to go to a youth jamboree in Brazil in July, while the faithful enthusiastically waved olive branches and braided palm fronds.
The square overflowed with a crowd estimated by the Vatican at 250,000 people. Pilgrims, tourists, and Romans jostled each other in an effort to glimpse Francis as they joined the new pope at the start of solemn Holy Week ceremonies, which lead up to Easter, Christianity’s most important day.
Keeping with his spontaneous style, the first pope from Latin America broke away several times from the text of his prepared homily to encourage the faithful to lead simple lives and resist the temptation to be sad when life’s obstacles inevitably come their way.
‘‘Don’t let yourselves be robbed of hope! Don’t let yourselves be robbed of hope!’’ Francis told the crowd, in an apparent reference to the economic difficulties people are grappling with as they try to find adequate work amid a poor job market in much of the world.
At the end of the two-hour Mass at St. Peter’s, Francis took off his red vestments, and wearing his plain white cassock and skull cap, climbed into an open-topped popemobile to circle through the excited crowd.
He leaned out to shake hands, kiss and pat the heads of infants passed to him by bodyguards, and give children the thumbs-up sign.
His security detail seemed to be reluctantly dealing with this get-close-to-the-people pontiff, scrambling around the vehicle to pick up this child or that one.