Letter-writers include Irish Redemptorist Fr. Tony Flannery, Paul Collins, Fr. Roy Bourgeois, Loretto Sr. Jeannine Gramick, St. Joseph Sr. Elizabeth Johnson, and Australian Bishop William Morris.
On Monday, Faustin-Archange Touadéra made his first visit abroad to see the pope at the Vatican, to thank Francis for his personal push for peace.
Sanders lauded Francis' repeated call to overcome a "globalization of indifference" -- labeling it "the most powerful name to the predicament of modern society."
The pope is not expected to grant an audience to Democratic presidential candidate Bernie Sanders in Rome this week.
An Italian journalist said he was given private documents by a Vatican official detailing problems with financial reforms and that he had a duty to publish them.
In a "humanitarian and ecumenical gesture," not a political one, Pope Francis was to join Orthodox leaders in personally meeting with hundreds of refugees and migrants stranded in Greece.
"There is no 'just war,'" the some 80 participants of the conference state in an appeal they released April 14.
NCR Today: The Council of Cardinals has begun organizing a general overview for the full restructuring of the Roman Curia.
Pope Francis has called on conference participants to reflect on how to enliven and strengthen the role of active non-violence in the face of aggression or conflict.
Italian Archbishop Carlo Viganò will be succeeded by French Archbishop Christophe Pierre.