The appeal is reflected in the conclusions of the World Congress, which gathered some 3,500 participants of civil and social organizations and representatives of various religions from 50 countries.
The purpose of the congress, which began Monday, was to provide the opportunity for intercultural and interreligious exchanges, reflection and dialogue to make the world a better place for families.
The conclusions of the congress include the appeal of 300 institutions "to the authorities of our respective countries and to the secretary-general of the United Nations, Kofi Annan" to declare themselves "against the initiative presented a few days ago by several countries to promote the sexual orientation of homosexuals and lesbians as a human right."
This initiative contradicts "human nature and dignity and the basic institutions of society: the family and marriage," the document notes.
The text states that the family "is an institution of natural law, origin of society" and its "basic and fundamental cell."
The family is made up of "the ensemble of persons who are linked through kinship, which can be through consanguinity, affinity or law, depending on the derivation from filiation, marriage or adoption."
The only ethical means to form a family is marriage, which is based on human nature and is constituted "by the union of a man and a woman," the congress emphasized.
"The union of persons of the same sex, being contrary to human nature, cannot be recognized as marriage," the document affirms.
The participants emphasized that "life and the respect of human nature are the first and fundamental rights of man"; therefore, "they must be respected from the very moment of conception."
Earlier this week in the United States, Massachusetts lawmakers passed a constitutional amendment to define marriage as the union of a man and a woman and to make their state the second in the country's history to create civil unions for homosexuals.
Lawmakers hope the amendment's passage, the first step in a process that could succeed no earlier than November 2006, would increase pressure on the Massachusetts Supreme Judicial Court to delay its order that the state begin performing homosexual "marriages" on May 17.