VATICAN CITY -- Pope Francis, laying out his hopes Wednesday for the just-begun year, urged people to work for a world where everyone accepts each other's differences and where enemies recognize that they are brothers.

"We are all children of one heavenly father. We belong to the same human family and we share a common destiny," Francis said, speaking from his studio window overlooking St. Peter's Square, jammed with tens of thousands of faithful, tourists and Romans.

"This brings a responsibility for each to work so that the world becomes a community of brothers who respect each other, accept each other in one's diversity, and take care of one another," the pope said.

Setting aside his prepared text for a moment, he expressed impatience with violence in the world. "What is happening in the heart of man? What is happening in the heart of humanity?" Francis asked. "It's time to stop."

He told the crowd this reflection was inspired by a letter he received from a man -- "maybe one of you" -- who lamented that there are "so many tragedies and wars in the world."

"I, too, believe that it will be good for us to stop ourselves in this path of violence and search for peace," Francis said.

In his remarks to the often-applauding crowd, he also expressed hope that "the gospel of brotherhood speak to every conscience and knock down the walls that impede enemies from recognizing that they are brothers."

Earlier, during his homily at New Year's Mass in St. Peter's Basilica, Francis spoke of humanity's journey in the year unfolding and invoked what he said were "words of blessing," explaining that they are "strength, courage and hope."

"Not an illusory hope," he added, "based on frail human promises, or a naive hope which presumes that the future will be better simply because it is the future."

In his first year as pope, Francis has charted a path for what he calls a "poor" church attentive to the needy. While offering new year's wishes to the crowd in the square, Francis pressed his campaign on behalf of the downtrodden.

"We are also called to see the violence and injustices present in so many parts of the world, and which cannot leave us indifferent and immobile," Francis said. "There is the need for the commitment of all to build a society that is truly more just and united."

Hearing "the cry of peace from peoples who are oppressed by war and by violence," Francis prayed that "the courage of dialogue and reconciliation prevail over the temptation for vendetta, arrogance, corruption."

The Catholic church dedicates Jan. 1 to the promotion of world peace, and St. Peter's Square, just as the pope appeared, marked the end of a peace march by thousands of people.

The marchers included Lula Teclehaimanut from Eritrea.

"The pope is truly our hope, not just for the Eritrean population but for the whole world, I believe," she said, recalling Francis' call for refugees to be welcomed and treated humanely. The refugees who risk their lives to flee to Europe, many of them by boat, include some from her homeland.

Among the many national flags waved by the peace marchers was that of Syria, with several Syrians among the participants expressing hope that peace reaches their country.