Tens of millions of people are "in chains" because of human trafficking and forced labour, and it is leading to their "dehumanization and humiliation," the Pope said at the ceremony Dec. 2, the UN Day for the Abolition of Slavery.
Every human person is born with the same dignity and freedom, and any form of discrimination that does not respect this truth "is a crime and very often an abhorrent crime," the Pope said.
Inspired by their religious beliefs and a desire "to take practical action," the Pope and 11 leaders representing the Muslim, Jewish, Orthodox, Anglican, Buddhist and Hindu faiths made a united commitment to help eradicate slavery worldwide.
The leaders signed the joint declaration at the headquarters of Pontifical Academy of Sciences in the Vatican Gardens. The signatories included: Anglican Archbishop Justin Welby of Canterbury; Rabbi David Rosen, international director of interreligious affairs for the American Jewish Committee; Ayatollah Mohammad Taqi al-Modarresi, an influential Shiite scholar; and representatives signing on behalf of Ahmad el-Tayeb, the grand imam of Al-Azhar University and Ecumenical Patriarch Bartholomew of Constantinople.
The declaration recognized that any action that fails to respect every person's freedom and dignity "is a crime against humanity."
"We pledge ourselves here today to do all in our power, within our faith communities and beyond, to work together for the freedom of all those who are enslaved and trafficked so that their future may be restored," it said.
"Today we have the opportunity, awareness, wisdom, innovation and technology to achieve this human and moral imperative," said the joint declaration, which was read aloud in English by a man from Ghana and in Spanish a woman from Mexico, both of whom had been victims of human trafficking and forced labour.
The initiative was organized by the faith-based Global Freedom Network, which was launched in March after a joint agreement by the Vatican, Al-Azhar University and the Anglican Communion.
Pope Francis thanked the men and women religious leaders for this "act of fraternity" on behalf of the countless numbers of women, men and children who are exploited for personal or commercial gain.
Despite global efforts, the scale of this "atrocious scourge" is on the rise and it often "disguises itself behind apparently acceptable practices" like in tourism and different forms of labour, he said.
The Pope asked that people of faith join together in the fight to end slavery and he called for the "steadfast support" of the world's governments, businesses and people of good will to "join this movement."
"We cannot tolerate that the image of the living God" present in every human being "is subjected to this most abominable form of trafficking."
According to the 2014 Global Slavery Index, almost 36 million people are currently caught in some form of modern slavery; the International Labour Organization estimates that organized crime networks reap about $150 billion a year from trafficking in persons, about 80 per cent of that from prostitution.