David's fall
1 Samuel 11:1 says "The following spring, the time of year when kings go to war, David sent Joab...to lay siege to the city of Rabbah. But David stayed behind in Jerusalem." Why do you suppose David stayed behind? Maybe he was over-confident in his past triumphs; maybe he had spring fever; or maybe he thought "I've worked hard enough, it's time I had a break." Regardless, this story holds an important lesson: Be careful of becoming complacent in the activities that are foundational in your life. Sure, it's important to take a vacation from time to time, but the essentials of life, the activities you build your life on, must not be put aside for long or else, carelessness, complacency or even laziness may creep in and have their way.
That's what happened to David. Verse 2 says "Late one afternoon David got out of bed after taking a nap and went for a stroll on the roof of the palace [where] he noticed a woman of unusual beauty taking a bath." What was David, the mighty warrior, the lover of the Almightly God, the leader of Israel's most successful army doing "strolling" after a nap in the middle of the afternoon while his army - the army he loved - was fighting a huge battle in the city of Rabbah? He was inviting catastrophe is what he was doing. And catastrophe came.
We know from verse 3 and following that David had the woman brought to him, he got her pregnant then had her husband (a trusted friend) killed on the front lines of the battle. And, because of his sin, he lost the son that was conceived in their sinful union and the story of his catastrophe is document for all the world to read.
David opted out of one of the things that kept him strong and indulged in something that made him weak. Beware of making the same mistake...it's easy to happen.