The hotel where I am staying has a complimentary copy of Time and this had Mother Teresa's face on the cover. Apparently her letters to her confessor had been made public and a book is due to come out about her more than 50 years doubt on her faith. Mother Teresa even doubted that God exists as she did her ministry to Calcutta's most downtrodden.
I think no sane person contests the public perception that Mother Teresa is a saint. After all in an age where consumerism reigns and we try to get as much for ourselves, her Missionaries of Charity nuns have been doing the exact opposite, giving. But what we see are the externals of what they are doing. We have no windows to their souls until they write about the troubles that rage their souls.
Catholicism does us great disservice when it canonises saints. For Catholics saints are frozen as icons and statues. As statues and icons we don't know how they dealt with lust (as in Augustine's case), greed (all saints), power (Thomas More), pride (Ignatius of Loyola), tomfoolery (Francis of Assisi) etc.
The same is true of secular saints Rizal and even Galileo had to battle their own doubts. They are now icons too.
The only way for us to know what how the saints did deal with their doubts is to read what they wrote. Unfortunately not all saints are good writers. The saints that we famously recall like Augustine, More, Ignatius of Loyola, John of the Cross wrote volumes. In this sense, Mother Teresa's letters definitely will change our idea of her. Her icon is forever smashed and we have to pray for her intercession through her living but indestructible icon and for Mother Teresa that is the poor.
That presents a big challenge for Pinoy Catholics. Our Catholicism is too much of externals (rosaries, images, processions, some papal pronouncements on contraception, being seen praying at Mass etc) but less of the internals. All religions command that we go beyond the externals if necessary smash it in Reformation. Perhaps this is the reason why religion declares we meet the Divine in another soul despite the scientism of Richard Dawkins and the literal but shackling interpretations of fundamentalists.