Palm and olive branches wave in St. Peter's Square , as Pope Francis leads a Palm Sunday service before more than 100,000 people.

The pope carries a pastoral cross carved from olive wood by the inmates of an Italian jail

He sets aside his prepared homily delivering an impromptu address, asking listeners to think about who they are.

(SOUNDBITE) (Italian) POPE FRANCIS, SAYING:

"Where is my heart? Who among these people am I like? This question will remain with us all week."

Palm Sunday marks the day that Jesus rode into Jerusalem to the cheers of the crowds the week before Christians believe he rose from the dead.