Charles Ellicott Commentary Ephesians 5:15

"Look therefore carefully how ye walk, not as unwise, but as wise;" — Ephesians 5:15 (ASV)

See then that ye walk (properly, how ye walk) circumspectly.—The word rendered “circumspectly” is properly strictly, or accurately—generally used of intellectual accuracy or thoroughness (Luke 1:3; Acts 18:25; Acts 18:28; 1 Thessalonians 5:2); only here and in Acts 26:5 (the straitest sect of our religion) of moral strictness.

The idea, therefore, is not of looking round watchfully against dangers, but of “seeing,” that is, being careful, “how we walk strictly;” of finding out the clear line of right, and then keeping to it strictly, so as not to run uncertainly. In the corresponding passage in the Colossian Epistle (Colossians 4:5) a similar admonition has especial reference to those without, and bids us have a resolute unity of aim, a distinct religious profession, amidst all the bewildering temptations of the world. Here it is more general; it bids people not to trust wholly to general rightness of heart, in which the spirit is willing, but to be watchful over themselves, and to be a law to themselves, because the flesh is weak.

Not as fools, but as wise.—This still further explains the “strictness,” for “wisdom” is the practical knowledge of the true end and purpose of life. (See above, Ephesians 1:8.) Anyone who does not have it, whatever his intellectual and spiritual gifts, is “unwise.”