VATICAN CITY — Pope Benedict XVI on Friday called for respect of all people without discrimination and the protection of children from war and violence as he celebrated the start of the new year.

Jan. 1 is also the Roman Catholic Church's World Day of Peace, and the pontiff issued an appeal to all armed groups to "stop, reflect and abandon the way of violence," even if it seems impossible.

"You will feel in your hearts the joy of peace, which you have perhaps long forgotten," Benedict said during the Angelus prayer.

He said peace begins by recognizing that men are brothers, not rivals or enemies.

"Peace begins with a look of respect that recognizes in another man's face a person, regardless of the color of his skin, nationality, language or religion," he said during Mass at St. Peter's Basilica.

The value of respect for all should be taught from an early age, Benedict said. Noting that classes containing children of different backgrounds are common, he said "their faces are a prophecy of the kind of humanity we are called upon to create: a family of families and peoples."

The 82-year-old pope put children, especially those hurt by conflict or forced to leave their homes, at the heart of his call for peace.

He said they make it evident that men are brothers because "despite differences, they cry and laugh the same way, have the same needs, communicate spontaneously, play together."

The painful images of children at the mercy of war and violence, their faces "disfigured by pain and desperation," are a silent appeal for peace, Benedict said.

The pope celebrated the Mass a week after he was knocked down by a woman on Christmas Eve.

In his comments, Benedict also renewed his call to protect the environment, saying the degradation of man leads to the degradation of the planet.