The Holy Father's comment was heard by thousands who had gathered today in St. Peter's Square to pray the Angelus.
"The birth of Christ helps us to be conscientious of what human life is worth, the life of each human being, from the first instant until natural death," the Pope said at midday from window of his study.
Reflecting on the mystery of Christmas, the Pontiff said: "In the God made man for us, we all feel loved, taken in, we discover that we are worthy and unique before the eyes of the Creator."
"To whomever opens their heart to this 'baby wrapped in swaddling clothes,' who lies 'in a manger,'" the Bishop of Rome said quoting the Gospel of Luke, "is offered the possibility of seeing with new eyes the reality of everyday."
"By his birth in the poverty of Bethlehem, he wants to accompany each one of us on our life journey," said Benedict XVI.
"In this world," added the Pope, "from the moment that he decided to make it his home, no one is a stranger."
"It is true, we are all here in passing, but it is Jesus who makes us feel as if we are at home on this Earth, made holy by his presence. He asks us, nonetheless, to make is a hospitable home for all," said the Holy Father.
The Pontiff continued: "This is precisely the surprise give of Christmas: Jesus came for each one of us and in him we have become brothers.
"From here comes the commitment to overcome each day more our prejudices, to take down the walls, and to eliminate those differences that divide us, or even worse, that set people and nations against one another, so as to build together a world of justice and peace."
On Christmas Eve, Benedict XVI said, the Child Jesus "will come for us. And he will also enter us, to live in the heart of each one of us."
"For this to take place it is indispensable that we be available and ready to receive him, and be willing to give him room in our hearts, in our families and in our cities," add the Pope.
The Holy Father prayed: "May his birth not find us unprepared to celebrate Christmas, forgetting that he is precisely the protagonist of the celebration."
The Pontiff mentioned especially those "that live Christmas sad and alone, sick and suffering: May the Virgin bring consolation to all of them."
The Pope will celebrate Midnight Mass in St. Peter's Basilica later today.
On Dec. 25, at noon, he will deliver a Christmas message and impart the blessing "urbi et orbi" (to the city of Rome and the world) from the central balcony of St. Peter's.