The final bit of information revealed, concerning a census carried out by David, contains 5 points of contention. All 5 supposed "contradictions" are discussed below.
But Amasa took no heed to the sword that was in Joab's hand: so he smote him therewith in the fifth rib, and shed out his bowels to the ground, and struck him not again; and he died. So Joab and Abishai his brother pursued after Sheba the son of Bichri. 2 Samuel 20:10 KJV The rift between Israel and Judah begins.
Trigger warning: these chapters discuss sexual assault/rape. From a protective brother to a vain rebel, Absalom his one of the more interesting people in the Bible and the narrative springboards a wide range of topics.
Bathsheba was a young woman just trying to stay clean, when David's wandering eyes got both of them into trouble. The hidden lesson in this passage confronts the double standard for men and women concerning sex.
These chapters mostly discuss the success of David. These successes include capturing of the ever-controversial city, Jerusalem, moving the ark, and upholding his promise to Jonathan. Also discussed is the rift that suddenly emerges between David and his first wife, Michal. Finally, we see a semi-messianic prophecy from the prophet Nathan.