2 Corinthians 10:3

Ἐν σαρκί. Emphatic by position. Everyone who has a body must ‘walk in the flesh’ and be liable to its weaknesses, such as the fear of men, the love of popularity, the liability to irritation, &c. But the missionary life of an Apostle, which resembles a campaign, is not conducted on such principles. The flesh is an abode (ἐν), but it need not be made a law (κατά). They might think that he had been wanting in vigour (2 Corinthians 10:2; 2 Corinthians 10:10), but they would find that indifferentism was not his guiding principle (2 Corinthians 13:1-4).

στρατευόμεθα. “The metaphor of a warfare, as applied to the Christian life, is a common one with St Paul, though it is more commonly used of the internal conflict of the Christian soul than of the external warfare waged against the evil around” (Lias): Romans 13:12-13; Ephesians 6:13-17; 1 Timothy 1:18; 2 Timothy 2:3-4. Comp. Isaiah 59:17; Wis 5:17-20; also the martyr’s exhortation, ἱερὰν καὶ εὐγενῆ στρατείαν στρατεύσασθε περὶ τῆς εὐσεβείας (4Ma 9:23). The Roman army was often before his eyes suggesting this metaphor, which he now works out in detail.

There is little doubt that the spelling στρατιας here is for στρατείας, ‘campaign,’ and not στρατιᾶς ‘army’: see critical note.