Instructions to children and fathers - but arguably (to say the least), all of the instructions are for the parents. Ironically, this is actually not part of our classes on parenting; it is part of a year-long series going through Ephesians chapters 5 and 6.
Just as light "exposes" things that were hidden in the dark, the Christian is to "expose" sin and avoid it. The passage is metaphor and not simile - Christians are not merely "like" a light; they ARE the light. Part of a year-long series in Ephesians chapters 5 and 6.