David's sin with Bathsheba carried extreme consequences.  For one thing, a person who no longer has moral authority also doesn't have the freedom to speak truth into the lives of others.  Perhaps that's why David never addressed the sin of his son, Amnon, and the violation of his half-sister, Tamar.  The story, however, is certainly a strong picture of how conflict that is not dealt with only grows larger.  Bitterness from the lack of resolution led to the murder of Amnon and the attempted overthrow of David's kingdom.  Who would have thought it could go so far?  The lesson is clear: address conflict early on before it causes even more irreparable damage.