What does 2 Samuel 11:1-17 mean?

In the spring of the year, the time when kings go out to battle, David sent Joab, and his servants with him, and all Israel. And they ravaged the Ammonites and besieged Rabbah. But David remained at Jerusalem. It happened, late one afternoon, when David arose from his couch and was walking on the roof of the king’s house, that he saw from the roof a woman bathing; and the woman was very beautiful. And David sent and inquired about the woman. And one said, “Is not this Bathsheba, the daughter of Eliam, the wife of Uriah the Hittite?” So David sent messengers and took her, and she came to him, and he lay with her. (Now she had been purifying herself from her uncleanness.) Then she returned to her house. And the woman conceived, and she sent and told David, “I am pregnant.” So David sent word to Joab, “Send me Uriah the Hittite.” And Joab sent Uriah to David. When Uriah came to him, David asked how Joab was doing and how the people were doing and how the war was going. Then David said to Uriah, “Go down to your house and wash your feet.” And Uriah went out of the king’s house, and there followed him a present from the king. But Uriah slept at the door of the king’s house with all the servants of his lord, and did not go down to his house. When they told David, “Uriah did not go down to his house,” David said to Uriah, “Have you not come from a journey? Why did you not go down to your house?” Uriah said to David, “The ark and Israel and Judah dwell in booths, and my lord Joab and the servants of my lord are camping in the open field. Shall I then go to my house, to eat and to drink and to lie with my wife? As you live, and as your soul lives, I will not do this thing.” Then David said to Uriah, “Remain here today also, and tomorrow I will send you back.” So Uriah remained in Jerusalem that day and the next. And David invited him, and he ate in his presence and drank, so that he made him drunk. And in the evening he went out to lie on his couch with the servants of his lord, but he did not go down to his house. In the morning David wrote a letter to Joab and sent it by the hand of Uriah. In the letter he wrote, “Set Uriah in the forefront of the hardest fighting, and then draw back from him, that he may be struck down, and die.” And as Joab was besieging the city, he assigned Uriah to the place where he knew there were valiant men. And the men of the city came out and fought with Joab, and some of the servants of David among the people fell. Uriah the Hittite also died.