Pope Francis urged Christians on Monday to forgo the greed, gluttony and materialism of Christmas and to focus instead on its message of simplicity, charity and love.

Francis celebrated a Christmas Eve Mass in St. Peter’s Basilica, opening a busy week for the pope that includes a Christmas Day message and blessing, a Dec. 26 prayer, New Year’s Eve vespers and a Jan. 1 Mass.

During his homily Monday, Francis lamented that many people find their life’s meaning in possessions when the biblical story of Christ’s birth emphasizes that God appeared to people who were poor when it came to earthly possessions, but faithful.

“Standing before the manger, we understand that the food of life is not material riches but love, not gluttony but charity, not ostentation but simplicity,” Francis said, dressed in simple white vestments.

“An insatiable greed marks all human history, even today, when paradoxically a few dine luxuriantly while all too many go without the daily bread needed to survive,” he said.

Francis has focused on the world’s poor and downtrodden, its refugees and marginalized, during his five-year papacy. The Catholic Church’s first pope from Latin American instructed the Vatican to better care for the homeless around Rome, opening a barber shop, shower and medical clinic for them in the embracing colonnade of St. Peter’s Square.

To extend his outreach this Christmas, Francis sent his trusted secretary of state, Cardinal Pietro Parolin, to Iraq to celebrate with the country’s long-suffering Christians.

Catholics are among the religious minorities targeted for Islamic State-inspired violence that has driven tens of thousands from their homes.

Parolin met Monday in Baghdad with Iraqi Prime Minister Adel Abdul-Mahdi. He is scheduled in the coming days to travel to northern Iraq to meet with Kurdish leaders in Irbil and to celebrate Mass in Qaraqosh in the Nineveh plains, near Mosul, according to the Vatican.

The Vatican has for years expressed concern about the exodus of Christians from communities that have existed since the time of Jesus, and urged them to return when security conditions permit.

Francis is likely to refer to the plight of Christians in Iraq and Syria during his Christmas Day “Urbi et Orbi” (To the city and the world) speech. He is scheduled to deliver it Tuesday from the loggia of St. Peter’s and again at Mass on New Year’s Day, which the church marks as its world day for peace.