10:3 war after the flesh. Paul often used a military metaphor to describe the Christian life (e.g., II Timothy 2:3-4). In this verse, “flesh” is not used theologically, but physiologically, referring to our natural human abilities. We “walk” like all natural men physically, but our warfare is conducted in the realm of the spirit, not with swords or guns.
10:4 not carnal. Our weapons are not “fleshly” weapons, but spiritual. In fact, Paul enumerates them in Ephesians 6:13-18, as “the whole armour of God,” namely truth, righteousness, peace, faith, salvation, the Word of God, and prayer. All too often, Christians and their churches try to do God’s work in ways that appeal to the flesh—great organizations, Christian entertainment, human wisdom and philosophy, beautiful facilities, glamorous advertising, and the like. These are “carnal” weapons, not the weapons provided by the Lord, and those who use them are in danger of eventual spiritual defeat, even if outward appearances seem impressive.
10:5 imaginations. The spiritual panoply of weapons ordained by God may not appear impressive outwardly to a humanistically oriented society, but it is only these that can pull down the strong holds of Satan in this world, casting down the humanistic “reasonings” (literal meaning of “imaginations”) of the leaders of this world’s educational and political systems. Otherwise the enemy will “spoil” us—that is, defeat us and despoil us of the carnal weapons we have tried to use (see Colossians 2:8).
10:5 every thought. “Thought” here is the same word as “mind.” Judicious use of our spiritual weapons—especially the one offensive weapon, “the sword of the Spirit, which is the word of God” (Ephesians 6:17)—will result in opening the blinded “minds” (note II Corinthians 4:4) of those who have rejected God and His Word, and capturing them for Christ. Thus, we are not to use such carnal weapons as bullets—or even ballots—in our battle for the human mind, but the mighty spiritual weapons in “the whole armour of God” (Ephesians 6:11).