Saint Teresa devoted her life to helping the destitute and the sick in slums in Kolkata.
When Pope Francis anointed sainthood on Mother Teresa at the Vatican, Kolkata - the city she had lived to serve - burst into tears of joy and chants of jubilation.
"We may have some difficulty in calling her 'Saint' Teresa," Pope Francis said. "Her holiness is so near to us, so tender and so fruitful that we continue to spontaneously call her Mother," he said hailing Saint Teresa of Calcutta as the personification of maternal love.
Seconds after the announcement, the Mother House in Kolkata - the headquarters of the Missionaries of Charity she had founded - it briefly rained. For Mother Teresa's devotees who had flown in from across the world to pray at the Mother Teresa tomb, it was more than just rain.
"Through Mother it is a blessing that we are getting," said a devotee who had come from Goa.
While her critics sometimes questioned her motives and accused her of practicing religious conversions, people of all faiths agreed Mother Teresa saw God in every person and that she served the people without discriminating.
Speaking to NDTV, Swami Saradatmananda from Ramkrishna Mission said, "She was always a saint as she saw God in humans she served, and did not look for God to serve. This is what Swami Vivekananda also said. She is truly a saint."
Mother's tomb was already full of prayer requests, but devotees from Europe, America, and southeast Asia kept leaving slips of paper with requests throughout the day.
"She is a hero and she represents peace," said Jessica Romero, who had come from France.
A church in Kerala's Thiruvananthapuram was the first to be named after Saint Teresa of Calcutta after the canonization. Devotees said the church build in 2003 was a testimony to what Mother Teresa meant to many people across the world.
"Mother Teresa herself is the biggest miracle. When I met her in 1994, I met a saint and not a noble laureate only. I am very happy," said a devotee Vilson Thampu.
The canonisation will also be celebrated in Skopje, the capital of modern Macedonia where Mother Teresa was born of Albanian parents in 1910 and became a nun aged 16.