This is particularly significant given the fact that the image of light is applied to both Jesus and his followers. In John 8:12, Jesus says, "I am the light of the world. Whoever follows me will never walk in darkness, but will have the light of life." And in Matthew 5:14-16, Jesus says, "You are the light of the world . . . let your light shine before others, that they may see your good deeds and praise your Father in heaven." These two passages surely go together - Jesus is our light, and we are likewise light to illumine others' darkness.
Mother Teresa later wrote in a letter in 1962, "If I ever become a Saint - I will surely be one of 'darkness.' I will continually be absent from Heaven - to light the light of those in darkness on earth." What's interesting about reading her letters is that even though she says she feels forsaken and that God is absent, her letters are infused with devotion to God. She takes for granted that God is present and living and active, yet she personally experiences a painful loneliness and yearning for God. The book's editor notes, "The most difficult aspect of her continuing interior darkness was her unquenchable thirst for God."
The irony is that she seems to have thought about God on a day-to-day basis far more than most of us Western Christians do! It is perhaps a sign of her saintliness that even in what she perceives to be her spiritual darkness, she was closer to God than most of us ever are. It's a paradox of the spiritual life that the times when God seems most distant may well be the times that we are actually closest to God.
[I've written about this in my book Grieving a Suicide in the chapter on "Where Is God When It Hurts?" The Gospel of Luke is bookended by two parallel stories of pilgrims on a road. At the beginning of Luke, Mary and Joseph are coming home from the Passover, and they think that Jesus is with them, but he isn't. At the end of Luke, coming home from another Passover are the disciples on the Emmaus road (most likely a husband and wife). They think that Jesus isn't with them, but he really is. The parallelism is surely intentional.]
Ten years after her death, Mother Teresa continues to be an inspiration to legions. (IVP is publishing a book next year, Finding Calcutta, about how Mother Teresa helped a university professor find her sense of calling, and Andy Crouch's forthcoming Culture Makers spends part of a chapter looking at Mother Teresa's cultural influence.) Even though she felt like she was dwelling in darkness, she is still one of the greatest contemporary examples of Christian service and devotion. We would do well to pray with her this prayer from Cardinal John Henry Newman that Mother Teresa used in a retreat in 1959:
Lead, kindly light, amid the encircling gloom,
LEAD THOU ME ON!
The night is dark, and I am far from home,
LEAD THOU ME ON!
Keep thou my feet I do not ask to see
The distant scene - one step enough for me.