Pope Francis has called for abolition of the death penalty as well as life imprisonment
He has also denounced what he called a "penal populism" that promises to solve society's problems by punishing crime instead of pursuing social justice.
"It is impossible to imagine that states today cannot make use of another means than capital punishment to defend peoples' lives from an unjust aggressor," the Pope said during a recent meeting with representatives of the International Association of Penal Law.
"All Christians and people of good will are thus called today to struggle not only for abolition of the death penalty, whether it be legal or illegal and in all its forms, but also to improve prison conditions, out of respect for the human dignity of persons deprived of their liberty. And this, I connect with life imprisonment. Life imprisonment is a hidden death penalty," he said.
Pope Francis noted that the Vatican recently eliminated life imprisonment from its own penal code.
According to the Catechism of the Catholic Church, cited by Pope Francis in his talk, "the traditional teaching of the Church does not exclude recourse to the death penalty, if this is the only possible way of effectively defending human lives against the unjust aggressor," but modern advances in protecting society from dangerous criminals mean that "cases in which the execution of the offender is an absolute necessity are very rare, if not practically non-existent”.
Interreligious dialogue ‘no substitute’ for mission – Benedict XVI
Retired Pope Benedict XVI said dialogue with other religions is no substitute for spreading the Gospel to non-Christian cultures, and warned against relativistic ideas of religious truth as "lethal to faith”.
He also said the true motivation for missionary work is not to increase the church's size but to share the joy of knowing Christ.
Benedict XVI’s words appeared in written remarks to faculty members and students at Rome's Pontifical Urbanian University, which belongs to the Congregation for the Evangelization of Peoples. Archbishop Georg Ganswein, prefect of the papal household and personal secretary to retired Pope Benedict, read the 1,800-word message at a ceremony dedicating the university's renovated main lecture hall to the retired Pontiff.
The speech is one of a handful of public statements, including an interview and a published letter to a journalist, that Pope Benedict has made since he retired in February 2013.
"The risen Lord instructed his apostles, and through them his disciples in all ages, to take his word to the ends of the earth and to make disciples of all people," Benedict XVI wrote.
"'But does that still apply?' many inside and outside the church ask themselves today. 'Is mission still something for today? Would it not be more appropriate to meet in dialogue among religions and serve together the cause of world peace?' The counter-question is: 'Can dialogue substitute for mission?'"
All wars begin in a jealous heart, Pope says
All wars begin in the human heart – a heart that is jealous and bitter and tears apart communities through misunderstandings and marginalisation, Pope Francis said.
"How wonderful if we would remember more often who we are, what Jesus Christ did with us: We are his body," members of the Church filled with the Holy Spirit's gift of new life in Christ and united in fellowship and love, he said at his weekly general audience in St Peter's Square.
The day also marked the feast day of St John Paul II, who "invited everyone to open the doors to Christ," said Pope Francis, who had canonised the Polish pope in April.
As the Church celebrated for the first time the memorial of St John Paul, Pope Francis recalled how he "reminded the whole world of the mystery of divine mercy. May his spiritual legacy not be forgotten, but drive us to reflect and act concretely for the good of the church, the family and society," he said in a greeting to pilgrims from Poland.