One of the tenants, the angles of Lutheran theology is that for Christ, preaching the law is an alien opus - a foreign or strange work, where as the proclamation of life and forgiveness and salvation is His proper work. This idea, this concept is vital for understanding how a preacher ought to approach preaching.
What is my goal, what do I desire for people? When I leave the pulpit, what am I to hope that people have received?
Ultimately, it has to be that they have received the forgiveness of their sins, life, and their salvation. Consider the Creeds - what is the focus there? God creates. "Who for us men and for our salvation". The Lord, the giver of life. The forgiveness of sins. This is what we confess God does, and so this is what His servants need to be about "doing" - giving out God's forgiveness.
The temptation for the preacher is to begin to love the alien work. To love, to elevate, to see as the "real" work the work of the Law. To think that the highest form of the pastoral arts is in reproof and correction.
Note, I am not arguing antinomianism - the proclamation of the law is an alien work but it is still a "work" - it is still to be done. But it's not the point.
The problem is this. We do not see the heart. We do not always judge rightly what the fruits of repentance are. But we can see outward displays of righteousness... and so the temptation for any pastor is to preach so that those outward displays are shown -- and we can fall into a "whatever works" approach... and fall in love with the alien.
Guilt can be a fantastic motivator to drive up the offering, but it doesn't forgive sins. Spectacle and prosperity preaching can drive up attendance, but it doesn't give life. And even as the pastor looks out and says, "Ah, see how wonderful things are" the Gospel is shuffled off.
Your job is not to "fix" people. Your job is not to make them better.
Oh, preach the Law, but preach it to kill them - to put their sinful flesh to death. Then do your proper work - give them life, give them Christ. That's your job.