Vatican City - Pope Benedict XVI marked the start of 2008 with an appeal Tuesday for world peace, calling it a "divine gift" and stressing family values as the foundation for it.
The Catholic Church celebrates Jan. 1 as World Day of Peace, and the pope used a midmorning Mass and a window appearance before thousands of faithful in St. Peter's Square to mark the occasion.
In his homily, he called for "the gift of peace: for our families, our cities and the whole world."
"We all aspire to live in peace, but real peace ... is not the simple conquest of man or the result of political agreements. It is, above all, a divine gift," Benedict said. At the same time, the pope added, peace is a "commitment that must be pursued with patience."
After leading the Mass at St. Peter's Basilica, the 80-year-old pope, dressed in ornate white and gold vestment, waved and smiled from his studio window to pilgrims gathered in the square.
Benedict returned to a theme central to his papacy, speaking of the importance of the traditional family based on the marriage between man and woman.
"Mankind is a big family," he said, stressing the link between family and peace. Benedict said mankind cannot live in peace unless it is inspired by the same values that hold a family together.
Family is the "first and irreplaceable educator of peace," Benedict said. Denying or restricting the rights of the family "threatens the very foundations of peace."
The remarks were in line with a strong Vatican campaign under Benedict for the protection of the traditional family and against proposals to extend rights to gay couples or other unions outside traditional marriage.
Taking an aggressive position in two overwhelmingly Roman Catholic countries, the Vatican has decried attempts by Italy's center-left government to give legal status to de-facto couples and denounced the Spanish social government for passing legislation recognizing gay marriage and facilitating divorce.
Thousands marched in Madrid on Sunday to defend the traditional family, with the pope praising the crowd via a live hookup. Months earlier, he applauded a similar rally in Italy.
"Whoever, even unknowingly, circumvents the institution of the family undermines peace in the entire community, national and international, since he weakens what is in effect the primary agency of peace," Benedict said Tuesday, quoting from his annual peace message to world leaders.