David was an adulterer (and plotted a murder).
While King David's men went off to war with the Ammonites
, he stayed behind in the comfort and security of his palace. From his palace wall, he spotted a beautiful married woman named Bathsheba, bathing. He summoned her to the palace and conceived a child with her. On top of that, David ordered the death of Bathsheba's husband. Their newborn died as a result of his sins, and it was only later that God rewarded the couple with their son, Solomon. (2 Samuel 11 and 12)