For they that are after the flesh do mind the things of the flesh; but they that are after the Spirit the things of the Spirit.
All Commentaries on Romans 8:5 Go To Romans 8
Ambrosiaster
AD 400
Paul says this because whoever obeys the temptation which comes through the flesh knows what the things of the flesh are…. Those who live according to the Spirit are those who have stomped on the lusts of the flesh by attacking sin. They have put the world behind them and although they still walk in the flesh they do not struggle according to the flesh. Their glory is not from men but from God. Dwelling in these spiritual works, they know what the things of the Spirit of God are and walk in his commandments. Commentary on Paul’s Epistles.