Paul's image of the believer's spiritual armor in Ephesians 6:10-17 clearly suggests the activity of warfare. And warfare suggests there will be captives. But in spiritual warfare, there are no physical conflicts or captives. Indeed, Paul says elsewhere that our battles are not in the physical realm as worldly battles are (2 Corinthians 10:3). So whom or what are we fighting? And whom or what do we take captive in order to win?
Recommended Reading:
Romans 12:1-2
It has been rightly suggested that spiritual warfare takes place "between the ears." That is, in the mind. That's where history's first spiritual battle took place. In the Garden of Eden, Adam and Eve had to weigh Satan's words against God's words and make a choice—the activity of the mind. They should have done what Paul says we should do: take "every thought into captivity to the obedience of Christ" (2 Corinthians 10:5). We must weigh every thought. If it is a lie, or dishonoring to God, we capture that thought and subdue it with the truths of God's Word.
We can only find victorious freedom by knowing God's truth (John 8:32).