Paul thought that the unique quality of the transformed life of a believer should be apparent to all. If you are not different from an unbeliever, you have no message to give, and you make the statement that Christ makes no difference.
Before meeting Christ, every person lived in ignorance of the truth, lacking spiritual life (Eph 2:1) and being enslaved to sin (2:2–3). The first verb phrase, “were at one time darkness,” is in the past tense, meaning this previous condition is no longer a reality. All believers were previously living in darkness. Paul described this dark life in Ephesians 4:17–19: “You should no longer walk as the rest of the Gentiles walk, in the futility of their mind, having their understanding darkened, being alienated from the life of God, because of the ignorance that is in them, because of the blindness of their heart; who, being past feeling, have given themselves over to lewdness, to work all uncleanness with greediness.”
Jesus said He is the “light of the world” (Jn 8:12): “God…commanded light to shine out of darkness, who has shone in our hearts to give the light of the knowledge of the glory of God in the face of Jesus Christ” (2 Cor 4:6). Because we, as believers, have the Light of the World “in our hearts,” we have become transmitters of this light: “You are the light of the world” (Matt 5:14). As the moon reflects the sun, so the believer must reflect the light of the Son of God, hence the command to “be continually or habitually walking as children of light.”
Paul wrote that we were to “cast off the works of darkness, and let us put on the armor of light. Let us walk properly, as in the day, not in revelry and drunkenness, not in lewdness and lust, not in strife and envy. But put on the Lord Jesus Christ, and make no provision for the flesh to fulfill its lusts” (Rom 13:12–14). In Ephesians 5:9–10, Paul amplifies the meaning of walking in the light, “(for the fruit of the Spirit is in all goodness, righteousness, and truth), finding out what is acceptable to the Lord.” If we are born anew as children of light, then we are to be consistent with what we have become. Paul told us to “walk worthy of the calling with which you were called” (Eph 4:1)—that is, walk in obedience to His word today and you will be different, pointing people to the Light of lights.
“Dear Lord, thank You for giving us the understanding of who You are and how You want Your children to live. What a difference from the selfish kind of life I was living! My great desire is to constantly live in a manner that makes me worthy of being called Your child.”
In order to practice this command today, I am going to …