Sean Callahan, president and C.E.O. of Baltimore-based Catholic Relief Services, returned last month from tours and consultations with C.R.S. partners in Ukraine, Ghana and Ethiopia.

The killing of Deborah Yakubu for alleged blasphemy and the reaction to it offer a stark depiction of the volatile divisions between Nigeria’s Muslim and Christian communities.

This week on “Inside the Vatican,” host Colleen Dulle speaks with Sant’Egidio’s Elizabeth Boyle about the lay group’s efforts to foster peace and friendship in South Sudan.

“I truly feel great sorrow at having to postpone this visit, which means so much to me," the pope said at his general audience on June 12.

Pope Francis has postponed “with regret” his visit to the Democratic Republic of the Congo and to South Sudan on the advice of his doctors so as “not to jeopardize the result of the therapy that he is undergoing.”

Pope Francis expressed his solidarity and closeness with Catholics in Nigeria after gunmen stormed a church and reportedly killed at least 50 people during a Pentecost Mass.