"and do not give the devil an opportunity."
A father read the story of Adam and Eve to his four year-old son. Afterward, he asked the boy what the story meant to him. "Not to play with snakes," his son replied. We may laugh at the boy's answer, but there's a lot of wisdom in it. When we nurture initial thoughts that are contrary to God's word, it's like opening the door when the devil knocks and inviting him to come in and play. But if we immediately take those same thoughts "captive to the obedience of Christ" (2 Corinthians 10:5), we are refusing to open the door, and the devil will flee (James 4:7).