Albert Barnes 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 circumspectly. Carefully, anxiously, concerned that you do not fall into sin. The word rendered "circumspectly"—akribōs—means, diligently; and the idea here is that they were to take special care to guard against the temptations around them and to live as they should.

Not as fools, but as wise. Not as the people of this world live, indulging in foolish pleasures and desires, but as those who have been taught to understand heavenly wisdom, and who have been made truly wise.