Worshippers carried palm fronds and olive branches and marched from the top of the Mount of Olives to the Old City of Jerusalem.
"This day is important, as you can see Christians waving palm branches the same way the crowds greeted Jesus when he entered Jerusalem by waving palm branches and covering his path with palm branches", he said.More news: Ecuador's president says Assange tried to use its embassy to spy
Thousands of Christian pilgrims took part in Palm Sunday celebrations in Jerusalem at the start of the Holy Week.
"Festive acclamations and brutal torture: the silence of Jesus throughout his Passion is profoundly impressive", Francis said in his homily. "This twofold mystery accompanies our entrance into Holy Week each year", he said.
Francis added that "one subtle form of triumphalism is spiritual worldliness, which represents the greatest danger, the most treacherous temptation threatening the church".More news: Steve Smith, David Warner named in Australia's Cricket World Cup squad
Palm Sunday, which falls on the last Sunday before Easter, is recognised by Christians as they mark the beginning of the journey to the cross where Jesus Christ was crucified. The pope called on young people not to be ashamed to show their enthusiasm for Jesus but at the same time not to fear following "him on the way to the cross".
Like every year the pope has a busy schedule this week.
On Holy Thursday, Francis will travel to the city of Velletri, south of Rome, to wash and kiss the feet of 12 inmates in a prison there to commemorate Jesus' gesture of humility toward his apostles on the night before he died.More news: Cavs Draw No. 2 Seed in Critical Lottery Tiebreaker