APTOPIX Vatican Christmas

Pope Francis delivers his "Urbi et Orbi" (to the city and to the world) blessing from the central balcony of St. Peter's Basilica at the Vatican, Friday, Dec. 25, 2015. (L'Osservatore Romano/Pool Photo via AP)

(AP)

Pope Francis says God opens heaven's doors to non-believers who "obey their conscience," shaking a widely-held assumption about Christian beliefs and reinforcing his image as the most progressive pontiff in history.

"You ask me if the God of the Christians forgives those who don't believe and who don't seek the faith," Francis wrote in a little known 2013 open letter published in the Italian newspaper La Repubblica. Francis was responding to questions from the paper's 91-year-old founder Eugenio Scalfari, reports Britain's The Independent.

"I start by saying -- and this is the fundamental thing -- that God's mercy has no limits if you go to him with a sincere and contrite heart," Francis wrote. "The issue for those who do not believe in God is to obey their conscience. Sin, even for those who have no faith, exists when people disobey their conscience."

The interpretation and translation of this remarkable letter have been questioned since its publication.

In Francis' Christmas Day prayer on Friday he indirectly denounced the Islamic State, decrying both the "brutal acts of terrorism" that struck Paris this year and the "monstrous evil" endured by the people of Syria and Libya. He also praised individuals and governments that have taken in refugees fleeing "inhuman conditions," The Associated Press reports.

Francis called on everyone "to welcome God's mercy in our lives, and be merciful with our brothers to make peace grow."

-- Douglas Perry

This post has been updated to correct the year the La Repubblica letter was originally published.