Right after you accept the Lord and listen to the Word of God, you can recognize your shortcomings very well. But the longer some people lead their Christian lives they may tend to judge others with the word of the truth that they've learned. It is arrogance that causes people to judge a situation with just at a glance. At first King David did everything only after asking God what to do when his kingdom was attacked by the Philistines. Sometime later, the Philistines attacked him again. Since David had experienced it before, he might have used the same or similar strategy based on his experience. However, he asked God again and kept asking God. When we humble ourselves and rely on God, we can be guided in a way that is prosperous in everything and all the time.