Spiritual adversaries must be fought with spiritual weapons. Although nearly everything we do, we do in the flesh, including our thinking. In 2 Corinthians God gives us strategies, including casting down imaginations. Notice that Paul doesn’t say one thing about bringing the devil into captivity, rather he says we take our own thoughts captive. Spiritual adversaries must be fought with spiritual weapons and our action in choosing our thought patterns and meditations are an important action in the battle.