Unfruitful Deeds (11-12): Paul adds a second imperative[1] to clarify how we are to relate to unbelievers. We are not to participate in the deeds of darkness. These are shameful deeds, such that we shouldn’t even talk about them! More than that, these are unfruitful deeds. How? They fail to meet the purpose for why we were created. Life is an opportunity to bear fruit for God’s glory and to reflect His character.[2] Deeds of darkness totally contradict this.[3] Put another way: deeds of darkness are a total waste of time![4] Moreover, those deeds incur the wrath of God (5:6). So then, what are we to do with those who still live this sinful lifestyle? Shun them? No. They need the truth of the gospel to be saved. And God gives us the honor of being His tools to open their eyes.[5]
Conversion (13-14): Paul builds on the light metaphor and shows how we can be used by Him. #1 Rebuke/correction: God uses us to expose people’s sin against the holy God. #2 Conviction of sin: the continual[6] exposure to light makes sin appear as it truly is: deserving of and incurring the wrath of God. #3 Change: deeds of darkness become deeds of light. What’s more? The sinner himself has now also become “light in the Lord” (5:8). We shed the light of God’s holiness,[7] and He converts sinners. Just as Scripture[8] predicted it, Christ shines upon sinners to save them (2 Cor. 4:5-6), and we get to take part!
[1] The first imperative is in 5:7. Both of these imperatives are consequences of God’s holy character (5:5-6).
[2] We exist for God’s glory (1:6, 12; 1 Cor. 6:20; 10:31; Rev. 4:11; Isa. 43:7) and to imitate Him (4:24; Col. 3:10).
[3] We weren’t saved based on good works (2:9; Tit. 3:5), but we were saved for good works (2:10; Tit. 3:8).
[4] Cf. 1 Pet. 1:18. Sin is utter foolishness/wastefulness. We view life as an opportunity for God’s will (5:15-17).
[5] God uses His people to draw sinners to Himself (cf. Matt. 5:16; 1 Pet. 2:9-12; Acts 8:4; 1 Cor. 14:24-25).
[6] Paul uses the imperfective tense to describe a continual exposure. We endure in our giving of God’s truth.
[7] When we proclaim the truth, we become the aroma of Christ, a fragrance of life or death (2 Cor. 2:14-16).
[8] Like 4:8, Paul summarizes OT revelation, namely, the expectation that the Messiah will illuminate sinners.