John Calvin Commentary Ephesians 5:15

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

See then. If believers must not neglect to drive away the darkness of others by their own brightness, how much less should they be blind as to their own conduct in life? What darkness will conceal those on whom Christ, the Sun of righteousness, has risen?

Placed, as it were, in a crowded theater, they should live under the eye of God and of angels. Let them stand in awe of these witnesses, though they may be concealed from the view of all mortals.

Dismissing the metaphor of darkness and light, he instructs them to regulate their life circumspectly as wise men, who have been educated by the Lord in the school of true wisdom. Our understanding must show itself by taking God for our guide and instructor, to teach us his own will.