Closer to the Seattle area Mark Driscoll has been eager to denounce fornication and yet he obviously admitted he did a bit of fornicating prior to marriage; he also has denounced stay-at-home dads as having forsaken their obligations while having admitted that for a time earlier in the history of Mars Hill he let Grace be the breadwinner, another case, it seems, of denouncing sins in others where you acutely feel guilt in yourself about your own moral failings. Driscoll's guilt about what he considers the sin of making the wife be the bread-winner of the family was so severe it colored his intepretation of 1 Timothy 5 to the point where his application of the text has pretty much nothing to do with any exegesis of the passage in question.
Paul wrote that when someone sins those who are spiritual should restore that sinner gently but to also be watchful so as to not fall prety to temptation themselves. One of the foremost problems of simply denouncing someone else's sin is that when we do this we give the impression that we would never sin in the way that someone else does. My very denunciation of "your" sin proves that I would NEVER even think of sinning in that way, right? Well, no. The lack of gentleness in the effort to restore or confront one in sin may (or may not, of course) be a sign that we are on the dangerous precipe of falling into the sin we are denouncing in others.
Don't believe me? Well, consider Ps 52 where David denounces Doeg the Edomite. Consider that in 1 Samuel 21 David lies about being on a mission from King Saul. Now I have heard it proposed that David in Ps 52 is rebuking himself and not Doeg but I admit to not seeing a ton of textual evidence to confirm this. I will leave it to actual OT scholars to tend to that for now. My observation is that despite David's passionate rebuke of Doeg the Edomite for working to kill innocent people and for his deceit David was just as capable of deceit.
Not only was David capable of the deceit at the start of 1 Samuel 21, in 1 Samuel 27 we see that David was willing to massacre village after village to keep his cover while living in Phillistine territory. Now that the Phillistines were the enemies of Israel could lead us to suppose that David was simply killing villages of the enemy camp and that that was okay. I am considering, however, another explanation for us to reflect on--David denounced Doeg for slaying innocent people and was far more accomplished in bloodshed toward women and children then Doeg.
The passion of David's denunciation of Doeg in Psalm 52 makes his own cavalier taking of the lives of others in the subsequent chapters of Samuel (1 Samuel 27 to the end of 2 Samuel) more rather than less offensive. If we see in the scriptures that the one true hero of the grand narrative of scripture is Yahweh and not people then we can learn from David as both a positive and negative example. As the apostle wrote, things were written down as a warning to us so that we would not fall prey to the same temptations. We should denounce sin but we must beware that in our denunciation of sin we are not secretly overcompensating and deceiving ourselves into thinking (and convincing others) that we are more virtuous than we actually are. Once you have deceived yourself you cannot help but deceive others.
Scripture attests in the book of Samuel that David, after lamenting that Doeg killed innocent people realized that he had failed by causing the death of innocent people. David himself would later massacre villages to keep his cover while living in enemy territory. One of the perils of denouncing sins in others is that we may find ourselves more guilty of that very sin than the person we have denounced. While David was a hero in Israelite history and killed a lot of Phillistines; while it is also true that he decimated Amalekites and so doing did the thing Saul declined to do; we should also bear in mind that as a critic of the taking of innocent blood David was more guilty than Doeg or Saul were in terms of sheer numbers.
The apostle Paul was not ignorant of these accounts in scripture, which may be why he took care to warn us by way of precept so that as we meditate on the scriptures we consider the life of a man like David as a concrete example.