Despite the formality of the occasion Pope Francis on Sunday declared to the tens of thousands of pilgrims gathered in St Peter’s Square that "her sanctity is so close to us, so tender and fruitful, that spontaneously we will continue to call her 'Mother Teresa'".
Speaking during Mother Teresa’s canonisation Mass (4 September) the Pope said God's will is explained in the words of the prophets: "I want mercy, not sacrifice."
Like Mother Teresa, he said, Christians are called not simply to perform acts of charity, but to live charity as a vocation and "to grow each day in love".
"Wherever someone is reaching out, asking for a helping hand in order to get up, this is where our presence – and the presence of the Church which sustains and offers hope – must be," the Pope said.
Mother Teresa, he added, lived out this vocation to charity through her commitment to defending the unborn and bowing down "before those who were spent, left to die on the side of the road".
She also "made her voice heard before the powers of this world so that they might recognise their guilt for the crime of poverty they created," Francis said. "For Mother Teresa, mercy was the 'salt' which gave flavour to her work, it was the 'light' which shone in the darkness of the many who no longer had tears to shed for their poverty and suffering."
For all Christians, especially volunteers engaged in works of mercy, the life of the saintly nun remains an example and witness to God's closeness to the poorest of the poor, he said.
An estimated 120,000 people packed the square, many holding umbrellas or waving fans to keep cool under the sweltering heat of the Rome sun. Upon hearing Pope Francis "declare and define Blessed Teresa of Kolkata to be a saint," the crowds could not contain their joy, breaking out in cheers and thunderous applause before he finished speaking.
The moment was especially sweet for more than 300 Albanians who live in Switzerland, but came to Rome for the canonisation. "We are very proud", said Violet Barisha, a member of the Albanian Catholic Mission in St Gallen.
Daughter of Divine Charity Sister Valdete, a Kosovan and one of the Albanian groups’ chaplains, said: "We are so happy and honoured. We are a small people, but have had so many martyrs."
Born in 1910 to an ethnic Albanian family in Skopje, in what is now part of Macedonia, Mother Teresa went to India in 1929 as a Sister of Loreto and became an Indian citizen in 1947. She founded the Missionaries of Charity in 1950.
Mother Teresa's simplicity did not keep the powerful away from the Mass, however. Some 20 nations sent official delegations to the Vatican for the canonisation.
Queen Sofia of Spain led a delegation. The president and prime minister of Albania attended, as did the foreign minister of India.
President Barack Obama sent a delegation led by Lisa Monaco, his assistant for homeland security and counterterrorism. The US delegation also included Ken Hackett, ambassador to the Holy See; Carolyn Woo, president and CEO of Catholic Relief Services; and Dominican Sister Donna Markham, president and CEO of Catholic Charities USA.
The first reading at the Mass was read by Jim Towey, who served as Mother Teresa's legal counsel in the United States and Canada from 1985 to 1997, and as director of the White House Office of Faith-Based and Community Initiatives, 2002-2006.