Mother Teresa of Calcutta, one of the most iconic figures of the 20th century, is set to become a Catholic saint on Sunday, in an open-air Mass led by Pope Francis due to attract hundreds of thousands of the faithful.
Born Agnes Gonxha Bojaxhiu in 1910, in Skopje, Macedonia, the ethnic Albanian Teresa helped the poor in India for most of her life. She founded the Missionaries of Charity in 1950 and gained worldwide recognition for her work, including a Nobel Peace Prize in 1979.
"The canonization of Mother Teresa invites us to look to her as a Christian hero, an outstanding model of the Christian life," the Canadian priest who promoted her sainthood cause, Father Brian Kolodiejchuk, said in March.
Teresa was a revered figure throughout the world, but not universally liked. Her hardline opposition to abortion and contraception, as well as readiness to accept donations from dictators, have been a matter of controversy.
Private letters published after her death in 1997 also revealed that for the last 50 years of her life she despaired over having lost a personal connection with Jesus, while she continued steadfastly to serve his cause.
Her canonization is one of the highlights of Francis' Jubilee of Mercy, a Catholic festival running until November 20. Kolodiejchuk said the timing was "fitting," given the pope's own focus on the destitute.
In a preface to a book on the soon-to-be saint, published in July, Francis recalled how giving to the needy is a key Christian teaching. "Mother Teresa made this page of the Gospel the guide for her life and the path to her holiness — and it can be for us, as well."
The pope will lead a Mass in St Peter's Square during which he will be asked three times, in Latin, to add Teresa to the pantheon of Catholic saints, whose number is unspecified but runs to the several thousands, at least.
Sainthood will be officially recognized as soon as Francis responds to the three petitions, still in Latin.
"We declare and define Blessed Mother Teresa of Calcutta be a Saint and we enroll her among the Saints, decreeing that she is to be venerated as such by the whole Church. In the name of the Holy Father, and of the Son, and of the Holy Spirit," he is expected to say.
Indian Foreign Minister Sushma Swaraj and other dignitaries from Teresa's adopted nation are scheduled to attend the Mass.
Several events are planned in the run up to the ceremony, including a prayer vigil on Friday, an audience in St Peter's Square with Francis on Saturday morning, followed in the evening by a veneration of Teresa's relics in a Roman basilica outside of the Vatican.
As the canonization falls on the eve of Teresa's feast day, which marks the anniversary of her death on September 5, 1997, there are expected to be more celebrations and religious services on Monday and later on in the week.
On September 7-8, pilgrims will be allowed to visit the room Teresa used on visits to Rome, in the convent of the Church of San Gregorio Magno near the Colosseum, where her Missionaries of Charity have a local branch.
Mother Teresa, the Roman Catholic nun soon to be canonized, was reviled, as well as revered in her lifetime. For many she was an angel, but for some a fanatic and an anti-feminist who associated with dictators.