In verse 12, Paul builds on the concept of living in this moment and making the most of the time we have. I love to watch sunrises and sunsets, and no matter how many times I’ve sat outside and watched the sun descend or the sun slide above the rim of the horizon, it still startles me how quickly we go from light to dark or dark to light. Metaphorically speaking, when we’re saved, we go from darkness into light. Symbolically, dark is used to describe spiritual lostness or evil acts. When we’re spiritually lost, we can’t see the truth, as if our eyes are closed. As for evil, you can stay hidden at night, so it’s easier to get by with foul deeds under the cover of darkness.
And then there’s light! Light signifies walking uprightly and honorably. If we’ve accepted Christ as Savior and sincerely made Jesus our Lord, then we have no business belonging to the night. We are to be that city on a hill; we are to be salt and light. Interestingly enough, the Greek word for “light” in this verse is “hoplon,” which is translated “weapon” or “tool.” Think taking up our spiritual weaponry and going to battle against the darkness.
Bottom line: We are people of light, and that should affect how we live.