John Chrysostom

"For our weapons are not of the flesh." For what sort of weapons are of the flesh? Wealth, glory, power, fluency, cleverness, circumventions, flatteries, hypocrisies, whatsoever else is similar to these. But ours are not of this sort: but of what kind are they? "Mighty before God." And he said not, 'we are not carnal,' but, "our weapons." For as I said, for the present he discourseth of the Preaching, and refers the whole power to God. …

Homily 21 on 2 Corinthians ↗

Theophylact of Ohrid

That is, not wealth, nor glory, nor smooth speech, nor flattery, nor hypocrisy, for such are the weapons of the flesh. He did not say: but spiritual (as, of course, one should have said in contrast to the word "carnal"), but – "mighty," hinting that carnal weapons are weak and powerless. See how far he is from pride. He did not say: we are mighty, but: "weapons, mighty through God," that is – God made them mighty. …

Commentary on 2 Corinthians ↗

Thomas Aquinas

That we are not carrying on a worldly war he proves when he says, for the weapons of our warfare are not worldly [carnal]; and first of all, from the weapons of warfare, as a fighter has weapons suitable to his warfare. Now it is plain that the weapons of those who fight according to the flesh, or wage war, are riches, pleasures, and worldly and temporal honors and power. …

Commentary on 2 Corinthians ↗