Reading this account, I am once again amazed at a couple of truths.
The first is the utter corrupting, destructive power of sin. Sin desires nothing less than our complete destruction and ruin. Left unchecked it will have all of us. We see in the accounts of Cain and Abel and Noah just how quickly and completely sin spreads.
The second is the ability and willingness of people (including myself) to allow sin to remain in our lives. We tell ourselves that our sin really isn't that bad or that we have it all under control. Sin desires to destroy us. We must, through the power of the Holy Spirit and with a clear understanding of the gospel, kill the sin that we are allowing to remain in our lives.
We must do this for our own sake, the sake of our families, and most importantly for the sake of the name of our God. Don't be deceived. No sin is ever under control. It is just waiting for you to become so accustomed to its presence that you don't even realize when it is moving in for the kill.