My friend Grant recently put me on to Thomas Merton. I have just finished his New Seeds of Contemplation. I highly recommend it. Here's a selection (emphasis mine):
To avoid sin and practice virtue is not to be a saint, it is only to be a man, a human being. This is only the beginning of what God wants of you....But the crucial problem of perfection and interior purity is in the renunciation and uprooting of all our unconcious attachments to created things and to our own will and desires.
In fighting deliberate and evident vices a planned strategy of resolutions and penances is the best way--if not the only way. You plan your campaign and fight it out and reshape the plan according to the changes in the aspect of the battle. You pray and suffer and hang on and give things up and hope and sweat, and the varying contours of the struggle work out the shape of your liberty.
When it ends, and when you have a good habit to work with, do not forget the moments of the battle when you were wounded and disarmed and helpless. Do not forget that, for all your efforts, you only won because of God, Who did the fighting in you.
Thomas Merton, New Seeds of Contemplation