GK Chesterton tells us that the saint is a medicine:
The saint is a medicine because he is an antidote. Indeed that is why the saint is often a martyr; he is mistaken for a poison because he is an antidote. he will generally be found restoring the world to sanity by exaggerating whatever the world neglects, which is by no means always the same element in every age. Yet each generation seeks its saint by instinct; and he is not what the people want, but rather what the people need. (from Chesterton's Saint Thomas Aquinas: The Dumb Ox)
When reading something like this, it is important to remember that while this paragraph comes from a book about St. Thomas Aquinas, when we say "saint" we do not necessarily mean some rare person whose name will go down in history as an exceptional Christian. Rather, we are all saints. In 2 Corinthians 5:20 Paul says, "We are ambassadors of Christ."
In fact, there are no exceptional Christian, because Christians are called to by virtue of being Christian be exceptional. Jesus taught the disciples, "You are the salt of the earth, and if the salt loses its saltiness, then how shall its saltiness be restored?" Salt is exceptional--it is both part of the food to which it has been added, but it is the exceptionally unique properties of salt that make it a valuable addition. Chesterton continued his thoughts on the medicinal nature of a saint:
Christ did not tell his apostles that they were only the excellent people, or the only excellent people, but that they were the exceptional people, the permanently incongruous and incompatible people... It is because they were the exceptional people, that they must not lose their exceptional quality... If the world grows too worldly, it can be rebuked by the Church, but if the Church grows too worldly, it cannot adequately be rebuked for worldliness by the world.What would it mean for us to be more exceptional? Notice that exceptional does not necessarily mean better than everyone else--it means different--unique. In what ways is God changing us so that we fit in the world much like salt fits in the stew--completely part of the stew, and yet with exception, giving the stew its flavor--restoring its worth; acting as medicine--exaggerating what the world neglects so as to restore health?
For if we as the Church cease to be the community of saints--the community of exceptional medicine; how will the sick world, how will sick souls become well?
UPDATE: An Example from Advent Conspiracy... Two "exceptional saints"