2 Corinthians 10:4 For the weapons of our warfare are not of the flesh but have divine power to destroy strongholds. We destroy arguments and every lofty opinion raised against the knowledge of God, and take every thought captive to obey Christ,
Ephesians 6:13-18 Therefore take up the whole armor of God, that you may be able to withstand in the evil day, and having done all, to stand firm. Stand therefore, having fastened on the belt of truth, and having put on the breastplate of righteousness, and, as shoes for your feet, having put on the readiness given by the gospel of peace. In all circumstances take up the shield of faith, with which you can extinguish all the flaming darts of the evil one; and take the helmet of salvation, and the sword of the Spirit, which is the word of God, praying at all times in the Spirit, with all prayer and supplication. To that end, keep alert with all perseverance, making supplication for all the saints,
1 Samuel 17:45-50 Then David said to the Philistine, “You come to me with a sword and with a spear and with a javelin, but I come to you in the name of the LORD of hosts, the God of the armies of Israel, whom you have defied.
Isaiah 2:11-12 The haughty looks of man shall be brought low, and the lofty pride of men shall be humbled, and the LORD alone will be exalted in that day. For the LORD of hosts has a day against all that is proud and lofty, against all that is lifted up—and it shall be brought low;
We walk according to the flesh in the sense that we all do. We are flesh and blood human beings, and we struggle with the same things the Corinthian Christians struggled with. However, Paul wants to make it clear that he does not war according to the flesh. Our weapons were not material or fleshly but spiritual, suited for spiritual war. Think about that and how it applies to how we should live, in order that in all we say, think, and do we honor and glorify Jesus Christ. Love rather than hate, Faith rather than self-reliance and self-assurance, Confidence rather than doubt, Power of the Holy Spirit rather than might of flesh, Joy rather than despair, Peace rather than conflict, Hope rather than fear and anxiousness, Kindness rather than hard-hearted and callous, Generous rather than selfish and self-centered, rejoicing rather than mourning, Holiness rather than polluted by worldly desires, Surrender to the will of God rather than the influence of self-reliance, etc…. The fleshly, worldly, and human way is to overpower, dominate, manipulate, and out-maneuver. The spiritual, Jesus honoring and glorifying way is to humble yourself, die to yourself, and let God show His resurrection power through you.
This reliance on fleshly/worldly methods and the habit of thinking this way is a false stronghold. It stubbornly sets down deep roots in the heart and mind, and it colors all of our actions and thinking. It is hard to let go of the thinking that values the things and ways of this world, but God’s power really can break down these strongholds. (Guzik)