After Mother Teresa passed away in 1997, the Vatican initiated the process of canonization. Before Mother Teresa could be beatified, a miracle had to be attributed to her intercession.
The Congregation for the Causes of the Saints opened an investigation into Mother Teresa shortly after her death and burial. The Congregation examined all available evidence to determine her merit for sainthood. Both published and unpublished material was studied. The famed atheist, Christopher Hitchens was invited to the Vatican to make the case against her canonization.
Following an extremely thorough review of the most intimate details of Mother Teresa's life and dealings, the Congregation announced they found no grounds to oppose her beatification.
Next, a miracle was required. That miracle came to Monica Besra, an Indian woman who had a massive tumor in her abdomen. According to Besra, she was wearing a locket containing the image of Mother Teresa. A beam of light emanated from the locket at the moment the miracle occurred. All subsequent medical scans revealed she was totally cured. There was no scientific or medical explanation for the miracle.
This miracle enabled the Vatican to proceed with her cause. Mother Teresa was beatified by Pope John Paul II on October 19, 2003.
On the occasion of her beatification, the Missionaries of Charity issued the following statement:
"We, the Missionaries of Charity, give thanks and praise to God that our Holy Father, Pope John Paul II, has officially recognized the holiness of our mother, Mother Teresa, and approved the miracle obtained through her intercession. We are filled with joy in anticipation of the Beatification that will take place in Rome on Mission Sunday, 19 October 2003, the closest Sunday to the 25th anniversary of the Holy Father's Pontificate and the end of the Year of the Rosary.
"Today, after three and a half years of investigation and study, the Church confirms that Mother heroically lived the Christian life and that God has lifted her up as both a model of holiness and an intercessor for all.
"Mother is a symbol of love and compassion. When Mother was with us, we were witnesses to her shining example of all the Christian virtues. Her life of loving service to the poor has inspired many to follow the same path. Her witness and message are cherished by those of every religion as a sign that "God still loves the world today." For the past five years since Mother's death, people have sought her help and have experienced God's love for them through her prayers. Every day, pilgrims from India and around the world come to pray at her tomb and many more follow her example of humble service of love to the most needy, beginning in their own families.
"Mother often said, 'Holiness is not the luxury of the few, it is a simple duty for each one of us. May her example help us to strive for holiness: to love God, to respect and love every human person created by God in His own image and in whom He dwells, and to care for our poor and suffering brethren. May all the sick, the suffering, and those who seek God's help find a friend and intercessor in Mother."
A long wait for a second miracle then followed. On December 17, 2015 Pope Francis announced a second miracle had been attributed to the intercession of Mother Teresa. The miracle involved a Brazilian man who was afflicted with tumors who was miraculously cured. This cleared the way for Mother Teresa's canonization.
Mother Teresa will be canonized on September 4, 2016 by Pope Francis.