In a message to South Africa President Jacob Zuma, Pope Francis said he offered a prayer to assure that Mandela's efforts to forge a new nation based on nonviolence, reconciliation and truth after the apartheid era "will inspire generations of South Africans to put justice and the common good at the forefront of their political aspirations."

The pontiff also asked God to "console and strengthen all who mourn (Mandela's) loss."

Mandela, who had been battling complications from a lung infection, died at his home in Johannesburg. He was 95.

Others commended Mandela for leading a peaceful transition to democratic rule after he was released from prison in 1990 after 27 years and his election in 1994 as South Africa's first black president.

President Barack Obama praised Mandela for striving to achieve a "democratic and free society in which all persons live together in harmony and with equal opportunities."

"We will not likely see the likes of Nelson Mandela again," Obama said during a press briefing Dec. 5. "So it falls to us as best we can to forward the example that he set, to make decisions guided not by hate, but by love, the never discount the difference that one person can make, to strive for a future that is worthy of his sacrifice."

Obama later in the day directed that flags be lowered to half-staff through sunset Dec. 9.

Secretary of State John Kerry in a statement said that Mandela "was a stranger to hate."

"He rejected recrimination in favor of reconciliation and knew the future demands we move beyond the past," Kerry said. "He gave everything he had to heal his country and lead it back into the community of nations, including insisting on relinquishing his office and ensuring there would be a peaceful transfer of power. Today, people all around the world who yearn for democracy look to Mandela's nation and its democratic Constitution as a hopeful example of what is possible."

The Catholic Church in Southern Africa said the death of Mandela brought great sadness and expressed its gratitude "for the sacrifice he made for all peoples of South Africa and for the leadership and inspiration he gave in leading us on the path of reconciliation."

"The greatest way we can acknowledge the life of Nelson Mandela is to strive for the ideals he cherished: freedom, equality and democracy, and to defend these ideals from those who would corrupt them," the Southern African Catholic Bishops' Conference said in a statement signed by Archbishop Stephen Brislin of Cape Town.

Mandela "never compromised on his principles and vision for a democratic and just South Africa where all have equal opportunities, even at great cost to his own freedom," the statement said.

When Mandela was released from prison, "the country was in turmoil and blood was being spilt almost daily," the bishops said.

"Through his leadership at that time, reinforced when he became president in 1994, he led the country on the path of reconciliation and peace, calling on South Africans to throw all arms of destruction into the sea. For this we shall always be indebted to him," they said.

In a personal statement, Archbishop Brislin said Mandela inspired the world. To honor Mandela's memory and continue the struggle for justice in South Africa and elsewhere, people must continue to seek a just order that includes all people, end discrimination, eradicate poverty, ensure that people live in dignity, have honest government untainted by corruption and care for the poorest and most vulnerable people in society, he said.

In a telephone interview Dec. 6, Bishop Kevin Dowling of Rustenburg, South Africa, said Mandela "lived the values that make life truly meaningful" and explained that the former president's "memory invites us to reflect on our call to be human beings with each other and for each other."

Bishop Dowling, vice chairman of the Southern African bishops' conference justice and peace department, helped establish the conference's parliamentary liaison office in Cape Town soon after Mandela was elected president.

The bishop recalled one day in November 1995 in which he met Mandela twice: once at the funeral of a king of the Bafokeng people and later in Oukasie, a tumbledown township that was the site of significant struggle during apartheid, for a gathering of the international Young Christian Workers.

In Oukasie, Mandela "headed straight for the kids who were there and there was such mutual joy at seeing each other," Bishop Dowling said, noting that Mandela "always had such smiling eyes and an exceptional love for children."

Then Mandela "asked me if the people at the meeting were all from different countries and when I confirmed this, he said, 'then I must greet them all personally.'"

"So there was this old man, who had had a very long day, shaking hands with every person there, asking them what country they were from. And the look on those young people's faces as he did that ...," Bishop Dowling said.

The values Mandela portrayed -- "understanding, compassion, reaching out to others -- are values I aspire to, and I think every one of us feels the same. He was what we yearn to be ourselves: profoundly human," he said.

Father Smangaliso Mkhatshwa, a South African priest who served in Mandela's cabinet, said the former president "was such a servant of the people that I sometimes thought, 'This man should have been a priest, not me.'"

The priest, who now heads South Africa's Moral Regeneration Movement, said that as deputy minister of education he once opened a new school in a poor rural area of South Africa in Mandela's presence.

"I felt so small and wondered why he didn't take over and officiate. But he put his hand on my shoulder and said, 'Smangaliso, this is your day. I am here to stand next to you and give you support.' That was the kind of man he was," Father Mkhatshwa said in a Dec. 6 telephone interview from Johannesburg.

Retired Anglican Archbishop Desmond Tutu lauded his fellow Nobel laureate as a man who showed a deeply divided nation how to come together. He downplayed rumors that South Africa would "go up in flames" in the wake of Mandela's death, saying such talk discredits South Africans' and Mandela's legacy.

"The sun will rise tomorrow, and the next day and the next. ... It may not appear as bright as yesterday, but life will carry on," he said.

The president of the U.S. Conference of Catholic Bishops also mourned Mandela's passing, calling him an icon.

"In his struggle against apartheid rule, Nelson Mandela was a light for peace and equality in his country and for the whole world," said Archbishop Joseph E. Kurtz of Louisville, Ky. "His years of imprisonment exemplified the suffering experienced by so many who seek justice. As president of South Africa, Mandela sought to undo the structures that marginalized and impoverished people - work Pope Francis is now challenging the entire world to imitate."

Archbishop Kurtz added that the prayers of the U.S. bishops were with the Mandela family and the people and church of South Africa.

"We thank God for his brave witness and for all men and women who work against injustice and seek, in the words of Pope John XXIII, 'to make the human sojourn on earth less sad.'"

Cardinal Timothy M. Dolan of New York, described Mandela as "a hero to the world" and that his defense of human rights against apartheid "made him a symbol of courage and dignity, as well as an inspiration to people everywhere."

"As Blessed Pope John Paul II noted during his visit to South Africa in 1995, Nelson Mandela was for many years, 'a silent and suffering 'witness' of your people's yearning for true liberation,' who, as president of South Africa, had to then 'shoulder the burden of inspiring and challenging everyone to succeed in the task of national reconciliation and reconstruction.' In succeeding in these crucial and difficult tasks, Nelson Mandela truly made the world a better place," the cardinal said in a statement.

In Chicago, Cardinal Francis E. George said in a statement that Mandela will be remembered "as a man whose personal integrity and the circumstances of life molded into a prophetic international figure."

"As a catalyst for reconciliation in South Africa, he became a model for how all of us can respond in the face of grave injustice," Cardinal George added.

Ray Flynn, former mayor of Boston and former U.S. ambassador to the Vatican, remembered Mandela's visit to the city in 1990 soon after his release from prison in a column in the Boston Herald Dec. 6.

Bostonians, especially Irish, Italian and Polish immigrants, identified with Mandela's anti-apartheid struggles because they also experienced bigotry and discrimination when they first arrived in the U.S., Flynn wrote.

"While he was in Boston, I saw the real greatness of Nelson Mandela. His humility and unique ability to connect with people was unparalleled," Flynn said.

"He taught us that it's not power or wealth that makes a leader great, but the power of truth and integrity."