A sharp contrast is observed between Ephesians 4:16 and v.17. The exhortation to act like light and not the darkness they had come from begins. The verse shown here is in this section and continues the thought why not read, right now, Ephesians 4:17 through all of chapter 5?
Therefore do not become partners with them; for at one time you were darkness, but now you are light in the Lord. Walk as children of light