"The Church's invitation to prepare for the Nativity is above all a command to us to open the gates of repentance, that Christ may enter our very being and be born anew in our hearts, and to offer our virtues to the newborn king. Instead of gold, we offer charity; instead of frankincense, prayer; instead of myrrh, repentance. Then, like the song of the angels and the adoration of the shepherds, our worship will be pure and our love without pretense."
-- Vassilios Papavassiliou, Meditations for AdventI'm so moved by the simplicity expressed here that I worry how to tie it into a paragraph of my own. Charity, prayer, and repentance are difficult things (newsflash!) because I find that they come in seasons -- there are times when I am like a spring, overflowing, and then there are other times when I find myself at the bottom of a well scratching in the dirt.
But my fickleness only serves as a reminder in its contrast with He-who-is-never-fickle. It is so important to keep these muscles in shape -- charity, prayer, repentance -- because I know a time will come when I'll need the strength as I'm scraping bottom.
C. S. Lewis writes that it is a great thing to remember that "...though our feelings come and go, His love for us does not. It is not wearied by our sins, or our indifference; and, therefore, it is quite relentless in its determination that we shall be cured of those sins, at whatever cost to us, at whatever cost to Him." (Mere Christianity).
And this is happiness because here is joy. During the Advent fast I can forget myself and become completely absorbed in what has to be done here and now. In denying myself I can notice the needs of others. In saying "no" to my own desires I am saying "yes" to His.