What does Ephesians 5:9 mean?

This verse includes a parenthetical statement. Like Ephesians 4:9–10, this is a side remark in the middle of another thought. In this case, Paul inserts an additional explanation of what it means to walk as children of light (Ephesians 5:8). Paul mentions the "fruit of light" as reference to the "result" of life. In other words, Christian obedience is found in "all that is good and right and true." All three words express the same concept of actions that are noble and pleasing to God.

Paul often refers to "good" in this letter. Believers are created to do "good" works (Ephesians 2:10), use "good" words (Ephesians 4:29), have "good" will (Ephesians 6:7), and will be blessed for doing "good" (Ephesians 6:8). Doing what is "right" is also a recurring concept in Ephesians. Believers are to live in true righteousness (Ephesians 4:24), obey their parents for this is "right" (Ephesians 6:1), and wear the breastplate of righteousness (Ephesians 6:14). Third, believers are to do what is "true," as noted in Ephesians 4:24: "created after the likeness of God in true righteousness and holiness."