Charles Hodge on Ephesians 5:15

V. 15. If this verse be considered as connected inferentially by οὖν with the preceding, then the association of ideas is: ‘If believers are bound to dispel the darkness from the hearts and lives of others, how careful should they be not to be dark themselves, i. e. they should walk as wise men.’ This however seems forced. The exhortation contained in this and the following verse is most naturally connected with that contained in verses 10 and 11. Believers as children of light are required to have no fellowship with the works of darkness, but rather to reprove them; see therefore, i. e. take heed therefore, πῶς ἀκριβῶς περιπατεῖτε, that ye walk circumspectly. Πῶς, however, does not mean that, though often used where ὅτι or ἵνα might be employed. It here as elsewhere means how, in what manner. "See in what manner ye render your deportment accurate." Ἀκριβῶς περιπατεῖν is to walk strictly by rule, so as not to deviate by a hair’s breadth. Not as unwise, but as wise. Paul often uses the word σοφία for divine truth. The σοφοί are those who possess this truth, which he had before called light, and the ἄσοφοι are those who have it not. So that wise and unwise are here equivalent to the enlightened and those in darkness. His exhortation, therefore, is that believers should carefully deport themselves not as the heathen and unrenewed, who have not the divine light of which he had been speaking, but as those who are enlightened from above and are therefore wise.