Don’t participate in (sugkoinoneo) darkness, Paul says (Ephesians 5:11). Communion with darkness is fruitless, sterile (akarpos). Instead of communing with the works of darkness, instead of joining them in one dead flesh, we are to “expose” the works of darkness. Elegcho, “expose,” can also mean “convict” (John 8:46), a word of the Spirit (John 16:8).
Verse 12 makes it clear that “deeds of darkness” are things “done . . . in secret.” These are the things to be rebuked and exposed. Things come to light (phaneroo) when rebuked/exposed by the light (v. 13).
But Paul doesn’t stop there. At least in some texts of Ephesians, Paul goes on with a small chiastic aphorism:
A. All things (panta), having been rebuked/exposed
B. by the light (phos)
C. become manifest (phaneroo).
A’. For everything (pan)
C’. that is manifest (phoneroo)
B’. is light (phos).
Paul alludes to the properties of natural light. Things naturally become illumined when they are brought out of the dark. They become recipients of light, and also reflectors of light. In the light, they become light.
But the dark and secret things that Paul is talking about in verse 13 are the things too scandalous to be mentioned (v. 12). Exposure of the secret things doesn’t just bring the darkness to light, so that the darkness, remaining dark, can be disposed of. Rather, when secret things are exposed by the light, they join the light, add to the light, are light.
Whatever does Paul mean? At the simplest level, when light rebukes a sinner, things he’s kept secret are brought to light, but he himself becomes a light among the lights of the world. As Paul puts it (obscurely quoting an obscure text): The “sleeper” arises from the dead as Christ shines on him (v. 14). The sleeper on whom Christ shines shines like Christ.
How rigorously should we push Paul’s claim? An adulterous affair takes place in secret; it comes to light; does it make sense to say that it then is light? Perhaps: Sins exposed become cautionary tales and proverbs of warning, and so provide light.
However this works practically, the theological point is profound: God spoke, and light shone in the darkness. Paul tells us not to share in the darkness but to rebuke it with light. When we do, light will shine. Speaking the word of rebuke, we replicate the fiat lux of the first day. We speak the word of light, and there is light.