A recipient of the Nobel Peace Prize, Mother Teresa spent much of her life working as a missionary with the poor in the Indian city of Kolkata.
To her fans, Mother Teresa was a saint during her lifetime, but to her critics she was a Catholic fundamentalist determined to save souls rather than bodies.
In an old Hindu temple in downtown Kolkata, there is a home for the destitute and the dying.
Mother Teresa established this place more than 60 years ago so that the city's poorest people didn't have to die on the streets.
Those who had lived like animals, she said, could die like angels, loved and wanted.
Sister Nicole, who works with the Missionaries of Charity, says Mother Teresa was a light for people in darkness - a woman who deserves to be made a saint.
"This official recognition gives us much joy. Also, I feel happy also for the sake of the poor."
Three people died in the Missionaries of Charity home the night before SBS's visit, but one man held on.
Saregoma comes from a village outside Kolkata and had come to the city to work as a porter.
But Saregoma fell sick and was found a few months ago on a railway station, destitute and close to death.
The sisters organised an operation for him at a local hospital and they believe he will live.
In the neighbouring women's dormitory, one of the new patients is an elderly woman who was also picked up from a railway station.
She arrived hungry and traumatised.
She hasn't been able to say her name.
She's been put on a saline drip and 23 year-old Elena Morer is holding her hand.
Ms Morer is from Barcelona and has come to Kolkata to volunteer at the home for the dying.
"I'm not a doctor, I don't know about medicine, but we all know about love and that is what they need. It's an international language, we can say. We just give love to them and that's what we do."
Agnes Gonxha Bojaxhiu was only 19 years old when she first stepped out into the chaos of Calcutta, as it was known then.
The Albanian nun spent 20 years with the Loreto order working as a teacher before she decided to leave and dedicate her life to the poorest of the poor.
The Missionaries of Charity was born.
This is Mother Teresa speaking in 1979.
"People who have nothing, who are wanted by no-one, who have become a burden to society, who have forgotten what is love, what is human touch. And for us, they are the children of God."
What began as a humble one-woman operation is now a major international organisation that operates in more than 100 countries.
Mother Teresa won the support of presidents and princesses.
Her biographer, Navin Chawla says she also had influence with the man who ran West Bengal for many years, the communist leader Jyoti Basu.
"When his cadres would go to him and say, 'Why are you supporting a Christian missionary?' he would say, 'You see how she works with the lepers? The day you can clean the wounds of a leprosy patient, on that day I will ask her to leave.' And that day never came."
Almost 20 years after her death, Mother Teresa remains India's most revered adopted citizen.
Many here believe the church didn't need a miracle to prove her sainthood because she was anointed one while she was alive.
They called her The Saint of the Gutters.
But she also has her critics.
One conservative Hindu organisation has accused the Missionaries of Charity of trying to convert people to Christianity.
The RSS's Jishnu Bose also accuses the organisation of running an exploitative marketing campaign.
"The Missionaries of Charity, whenever they're marketing our poverty, this is a direct insult to the people of Kolkata."
Mother Teresa has also been criticised for her anti-abortion views, for accepting money from dictators and for providing inadequate medical care in her hospices.
But biographer Navin Chawla, a self-described "near-atheist Hindu", says much of the criticism came from the West and went largely unnoticed in India.
Mr Chawla is a former election commissioner of India who knew Mother Teresa for more than 20 years.
Her asked her many times whether she tried to convert people.
"She said, 'Yes I do convert, I convert you to be a better Hindu, a better Christian, a better Catholic, a better Jew, a better Sikh, a better Muslim. When you've found God it's up to you to do with him what you want.'"
Kolkata is often called the City of Joy, but for thousands it remains a place of despair.
In Rome, the Albanian nun who worked on these streets will become a saint.
And here in Kolkata, as the rain falls, a baby boy will sit under a bridge with nowhere to call home.
