Rev. David Peterson is the pastor of Redeemer, Fort Wayne. His Cyberstones blog post, Preaching Law to the Choir, got my attention simply from the title, of course! It talks about the appropriate preaching of the law to a congregation.
The law needs to convict the listeners of their sins as opposed to getting them to agree that the behavior is wrong.
Our pride gets in the way as usual. Rev. Peterson notes that old-time Reformation Services included preaching against the pope. Since none of the people present were the pope, preaching the law in this manner does not convict the listeners of their own sin.
We preach the Law not to condemn the absent, but to condemn sin and sinners, to teach sinners the hard and humility work of examining themselves, of confessing the pitiful lies we've told and our self-absorption, our thousand pretend ways meant to fool ourselves and our neighbors into thinking we are better than we are, to confront what is really in us and who we really are, not as a way of nagging us to better behavior or to make us feel superior to other people, but to show us how great and selfless Christ's rescue is.
How beautiful, that even though our sinful nature tells us we are doing fine, the Law comes around and convicts us that we are not, the the Gospel kicks in and even though we do not deserve it Christ's forgiveness, bought for us on the cross, is offered.