This is a lovely, quick read (though very deep) that draws and challenges you out of yourself to see where you're supposed to be in relation to God and to others. It's a series of three sermons that were given by then Cardinal Ratzinger during Advent and are perfect reading for this season.
Here are a few quick quotes to give you a taste of what I mean:
When we reflect on such things, we shall simply no longer be able to divide history into ages of salvation and of iniquity. If we then extend our vision and look at what Christians (that is, those people we call 'redeemed') achieved in the world by way of iniquity and devastation, in our own century and the previous centuries, then we will be equally incapable of dividing the peoples of the world into those who are saved and those who are not. If we are honest, we will no longer be able to paint things black and white, dividing up both history and maps into zones of salvation and iniquity. History as a whole, and mankind as a whole, will appear to us rather as a mass of gray, in which time and again there appear flickers of that goodness which can never quite be extinguished, in which, time and again, men set out toward something better, but in which also, time and again , collapses occur into all the horrors of evil.
Yet when we reflect like this, it becomes plain that Advent is not (as might perhaps have been said in earlier ages) a sacred game of the liturgy, in which, so to speak, it leads us once more along the paths of the past, gives us once more a vivid picture of the way things once were, so that we may all the more joyfully and happily enjoy today's salvation. We should have to admit, rather, that Advent is not just a matter of remembrance and playing at what is past - Advent is our present, our reality: the Church is not just playing at something here; rather, she is referring us to something that also represents the reality of our Christian life. It is through the meaning of the season of Advent in the Church's y ear that she revives our awareness of this. She should make us face these facts, and make us admit the extend of being unredeemed, which is not something that lay over the world at one time, and perhaps somewhere still does, but is a fact in our own lives and in the midst of the Church.
And one more passage...
Being a Christian means having love; it means achieving the Copernican revolution in our existence, by which we cease to make ourselves the center of the universe, with everyone else revolving around us.
If we look at ourselves honestly and seriously, then there is not just something liberating in this marvelously simple message. There is also something most disturbing. For who among us can say he has never passed by anyone who was hungry or thirsty or who needed us in any way? Who among us can say that he truly, in all simplicity, carries out the service of being kind to others? Who among us would not have to admit that even in the acts of kindness he practices toward others, there is still an element of selfishness, something of self-satisfaction and looking back at ourselves? Who among us would not have to admit that he is more or less living in the pre-Copernican illusion and looking at other people, seeing them as real, only in their relationship to our own selves? Thus, the sublime and liberating message of love, as being the sole and sufficient content of Christianity, can also become something very demanding.
It is at this point that faith begins. For what faith basically means is just that this shortfall that we all have in our love is made up by the surplus of Jesus Christ's love, acting on our behalf. He simply tells us that God himself has poured out among us a superabundance of his love and has thus made good in advance all our deficiency. Ultimately, faith means nothing other than admitting that we have this kind of shortfall; tit means opening our hand and accepting a gift.