The pope stressed the need for education of young people to "form mature individuals capable of overcoming division and antagonism, and to restore the fabric of relationships for the sake of a more fraternal humanity" in many societies where solidarity is lacking.
"There is, in fact, a tendency, in many parts of the world, to be self-absorbed, to defend acquired rights and privileges, and to view the world within a narrow horizon that treats the elderly with indifference and no longer welcomes the newborn. The general aging of the world population, especially in the West, is a sad and emblematic example of this," Francis said.
He said that 30 years after the fall of the Berlin Wall, it is still easy to erect barriers.
"The Berlin Wall remains emblematic of a culture of division that alienates people from one another and opens the way to extremism and violence. We see this more and more in the hate speech widespread on the internet and in the social communications media. Rather than walls of hatred, we prefer bridges of reconciliation and solidarity; rather than what alienates, we prefer what draws people closer together," he said.
Pope Francis said that he witnessed solidarity and signs of peace and reconciliation during his apostolic visit to Africa last year. He reflected on his seven apostolic journeys to 11 countries in 2019, the year with the most visits outside of Italy in his pontificate.
In 2019, Pope Francis visited Panama, the United Arab Emirates, Morocco, Bulgaria, North Macedonia, Romania, Mozambique, Madagascar, Mauritius, Thailand, and finally Japan.
"A world without nuclear weapons is possible and necessary," the pope told diplomats, repeating his message from his visits to Hiroshima and Nagasaki in November.
Pope Francis said that the Review Conference of the Treaty on the Non-Proliferation of Nuclear Weapons in New York in April and May will be critical to find consensus on ways to implement this international legal instrument.
"Hope requires courage. It means acknowledging that evil, suffering and death will not have the last word, and that even the most complex questions can and must be faced and resolved," he said.
The 70th anniversary of the proclamation of the Assumption of the Blessed Virgin Mary this year "invites us to look ahead to the completion of our earthly journey to the day when justice and peace will be fully reestablished," Pope Francis said.