The definition of diligence is steadfast application, assiduousness and industry. The reason I chose Mother Teresa to represent this virtue is because she was the very definition of Christian steadfastness. She worked for decades among India's dying poor, running a hospice for those who had no one to be with them in their last hours on earth.
Only after her death did we discover that she suffered from a dark night of the soul for most of her life. For decades she did not hear the voice of God, she did not sense His presence and, at times, she even doubted whether or not He was there at all.
And yet, she kept on. She cared for the poor and for the sisters in her care, she traveled and gave controversial speeches to powerful people and greeted those who came to see her. She met with her confessor and poured out her heart to him in letters. She steadfastly worked for Christ.
"Yesterday is gone. Tomorrow has not yet come. We have only today. Let us begin." — Mother Teresa