David repented of his sins of adultery and murder. The Lord forgave David, but the child conceived by his adulterous relationship died, because sin naturally results in death (see Rm 6:23). David was able to prevent the law of sin and death from immediately causing his own death. He did this by repenting, for the law of repentance results in life and joy (see Lk 15:32). David also hoped to save his child's life by doing penance. "David besought God for the child. He kept a fast, retiring for the night to lie on the ground clothed in sackcloth" (2 Sm 12:16). The law of penance leads to life, healing, and reparation. However, in this case the law of penance was not strong enough to override the law of sin and death.
To understand this, think of an airplane taking off. The law of gravity is always in effect, but an airplane weighing several tons can fly because other laws of aerodynamics are also in effect.
In the new covenant, the law of penance is much stronger than in the old covenant because the Lord has given His Church the power to bind and loose (Mt 16:19). This law of binding and loosing makes it possible for the Church to give indulgences, that is, to make our penance much more powerful. Therefore, our prayer, fasting, and sacrifices will be much more effective than David's. Consequently, we have a great responsibility to do penance.
|Rescript: In accord with the Code of Canon Law, I hereby grant the Imprimatur ("Permission to Publish") for One Bread, One Body covering the period from December 1, 2009 through January 31, 2010.
†Reverend Joseph R. Binzer, Vicar General of the Archdiocese of Cincinnati, June 4, 2009.