|David and Saul|
In First Samuel 24, we are in the midst of the conflict between the outgoing King Saul and the rising king-to-be David. David finds a sleeping Saul in a cave, and cuts of a corner of the royal robe. Later, he shows the sample to Saul to prove that he could have killed his oppressor, but refrained, out of respect for the Lord's Anointed (verse 10). David explains (I Samuel 24:12-13), "May the Lord judge between me and you, may the Lord avenge me against you, but my hand shall not be against you. As the proverb of the ancients says, ‘Out of the wicked comes wickedness.’ But my hand shall not be against you."
I especially want to focus on the one phrase, "Out of the wicked comes wickedness." That this proverb is true is shown by its later use by David's descendant, the Lord Jesus Christ: "What comes out of the mouth proceeds from the heart, and this defiles a person. For out of the heart come evil thoughts, murder, adultery, sexual immorality, theft, false witness, slander. These are what defile a person" (Matthew 15:18-20).
This is the doctrine of total depravity. Both David and Jesus are teaching the biblical truth that we sin, every one of us, because we are sinners. Our hearts are wicked (Jeremiah 17:9)! This is contrary to the common belief that committing sins makes us into sinners. All of Scripture teaches this, though our human hearts reject it. In fact, our natural reaction to the doctrine is subjective proof of its truth!