Our minds are bombarded daily by thousands of messages, many of which are at direct odds with the truth and purity of God. And they matter because unfiltered crud corrodes our thinking, dulls our conscience and small bits at a time can replace truth with error. No matter how good our theology or precise our doctrine, unless we are vigilant with what and how we process all of those messages we are at risk.
Paul makes this point in 2 Corinthians 10:4-5 when he writes, "
Obviously the divine power has to do with the Holy Spirit within us which has the power to demolish strongholds (of the enemy). This includes strongholds in our own lives whatever they may be that set themselves up against the truth of God. But that takes vigilance and Paul's next statement speaks to that: "and we take captive every thought to make it obedient to Christ."
Think about this. Our days are made up of a series of thoughts, messages, ideas, temptations, attitudes - all that moves through our brains. Paul says that he pays attention to the information traveling through his mind in order to take captive every thought to make it obedient to Christ, or to synthesize it in light of what God has to say.
We are not at the mercy of the messages that come our way. The Holy Spirit will help us if we ask to be aware of those messages and where they differ from the truth of God or the holiness of God. We have the ability to take every thought captive if we live with an awareness of the Holy Spirit and choose to think critically.