VATICAN CITY (BP) — Southern Baptists’ lead ethicist has affirmed “a strong statement” by Pope Francis on traditional marriage during the pontiff’s opening address at the Vatican colloquium on “the complementarity of man and woman in marriage.”

“Pope Francis made clear that male/female complementarity is essential to marriage, and that this cannot be redefined by ideology or by the state,” Russell D. Moore, president of the Ethics & Religious Liberty Commission, told Baptist Press in written comments from the Vatican. “I am glad to hear such a strong statement on this, and on how an eclipse of marriage hurts the poor and the vulnerable.”

Moore and Rick Warren, pastor of Saddleback Church, a Southern Baptist congregation in the Los Angeles area, are the two American evangelicals scheduled to address the Nov. 17-19 Vatican gathering.

The pope told 300 representatives of various world religions Nov. 17 that living in a home with a father and a mother is crucial to a child’s wellbeing.

“The family is the foundation of co-existence and a guarantee against social fragmentation,” Francis said, according to a transcript of his address posted online by Vatican Radio. “Children have a right to grow up in a family with a father and a mother capable of creating a suitable environment for the child’s development and emotional maturity.”

Francis added that “the contribution of marriage to society is indispensable.”

“Complementarity” — a term referencing the unique roles of men and women in a variety of contexts — is “at the root of marriage and family,” the pope said.

“When we speak of complementarity between man and woman in this context, let us not confuse that term with the simplistic idea that all the roles and relations of the two sexes are fixed in a single, static pattern,” the pope said. “Complementarity will take many forms as each man and woman brings his or her distinctive contributions to their marriage and to the formation of their children.” Complementarity “is not just a good thing but it is also beautiful.”

Francis acknowledged that marriage is “in crisis” and said its decline has adverse effects on society.

“We now live in a culture of the temporary, in which more and more people are simply giving up on marriage as a public commitment,” Francis said. “This revolution in manners and morals has often flown the flag of freedom, but in fact it has brought spiritual and material devastation to countless human beings, especially the poorest and most vulnerable. Evidence is mounting that the decline of the marriage culture is associated with increased poverty and a host of other social ills, disproportionately affecting women, children and the elderly. It is always they who suffer the most in this crisis.”

To protect marriage, it is “essential that we foster a new human ecology and advance it,” Francis said. The pope’s mention of “ecology” — the study of living organisms and their environments — referenced the fact that traditional family is the best environment for human flourishing.

“Social environments, like natural environments, need protection,” Francis said. “And although the human race has come to understand the need to address conditions that menace our natural environments, we have been slower to recognize that our fragile social environments are under threat as well.”

Younger generations in particular must “not give themselves over to the poisonous mentality of the temporary” and instead realize that “permanent commitment to solidarity, fidelity and fruitful love responds to the deepest longings of the human heart,” Francis said.

The pope closed his remarks by announcing that he will travel to Philadelphia in September for the Eighth World Meeting of Families.

Other scheduled speakers this week at the Vatican marriage colloquium include:

— N.T. Wright, popular Christian author and professor at the University of St. Andrews.

— Charles Chaput, Catholic archbishop of Philadelphia.

— Jonathan Sacks, professor at both New York University and Yeshiva University and former chief rabbi of the United Hebrew Congregations of the United Kingdom.

Representatives of Islam, Buddhism, Hinduism, Mormonism and the Sikh religion will also address the Vatican colloquium.

The gathering comes at a time when marriage as a permanent union of only a man and a woman is threatened, especially in the United States: The percentage of American adults who have never married is at an all-time high; cohabitation and divorce are problems in the culture and the church; and judicial rulings have set the stage for same-sex marriage to be legal in 35 states, though the Supreme Court likely will take up the question of gay marriage following the Sixth Circuit Court of Appeals’ affirmation gay marriage bans in four states. In addition, the religious freedom of Americans who decline to provide their services for same-sex weddings based on their convictions increasingly is imperiled.