Leviticus 16:29-30. "And it shall be a statute to you for ever that in the seventh month on the tenth day of the month, you shall afflict yourselves, and shall do no work ... for on this day shall atonement be made for you, to cleanse you; from your sins you shall be clean before the Lord." This is God establishing Yom Kippur, the Jewish day of atonement. He tells Moses it is to be a statute forever, and it remains one of the holiest days for the Jews, second only to Rosh Hashanah, so it has been a statute for as much of forever as we know of!

Of the two main high Jewish holy days, one is a day of "affliction" and atonement, and the other is a day of celebration. God knows us so well! He knows that we need the one to fully enjoy the other. We can and must celebrate sometimes, there is much to celebrate in this beautiful world, but we also must recognize our sinfulness and how we have harmed the world with it. Thus, the day of atonement is necessary to fully enjoy the day of celebration.

Can we really fully enjoy the gifts God gives us when we are burdened by our sin? We try, but there is always a note of hollowness. Often, rather than looking inward, we then try harder - filling ourselves with as many "good" things as we can get. This is the road to despair, and often to addiction. Rather than facing our own sinfulness and atoning for it, we run from it, to no avail. God wants us to face our sin, not because He wants us to suffer, but because He wants to cleanse us and make us free, as He does in our sacrament of penance 

We are currently in the Advent season, a season of preparation for the coming of our Savior, our second most joyful celebration. During this season, we are to be looking inward, facing our faults and confessing our sins so that we can be ready for the day of celebration. The same is true of the season of Lent, which leads to our highest holy day, Easter. In all the ways He leads us to repent and atone, God shows us that we cannot enjoy the days of celebration without the days of preparation.