τὰ γὰρ κρυφῇ γινόμενα ὑπ᾽ αὐτῶν αἰσχρόν ἐστιν καὶ λέγειν, τὰ δὲ πάντα ἐλεγχόμενα ὑπὸ τοῦ φωτὸς φανεροῦται, πᾶν γὰρ τὸ φανερούμενον φῶς ἐστιν. For the things in secret performed by them are filthy also to speak, but all things exposed by the light are made visible, for every thing made visible is light.
Paul is now drawing another contrast between the sons of disobedience and the children of light. Building off of the light and darkness metaphor, Paul resorts to “secret” language to speak of the disobedient. It is implied that what is being done in secret is done in darkness. He says that what they do in secret should not even be mentioned due to the filthy and morally base nature of their actions. He has already mentioned some of what they do in v. 3, but he was not very specific. Paul exhorts his readers not to speak of their secret deeds; speaking of such deeds would be shameful in itself. Instead of talking about it, Paul states that by exposing their deeds through the light, they will be revealed. In other words, they will become known for what they really are, that is, morally depraved. Paul makes this statement on the simple ground that any thing that comes into the light becomes visible and is therefore light.
For it is shameful also to speak of the things performed by them in secret, but all things exposed by the light are revealed, for every thing that is revealed is light.
Christians should allow their own actions to act as a testimony to the not so distant onlookers. Our actions themselves are a ray of light in the midst of darkness. They speak against morally depraved deeds as a natural contrast. We do not need to tell stories and speak of what some people have done in specific detail. We need only to reveal those deeds in contrast with our own. Such a contrast reveals the disobedient for what they truly are. The important thing to remember is that our actions must be morally pure in order to have its desired effect. If we are not distinguishable from the darkness, then our role as light will diminish. Therefore, we have a responsibility to do what is good, right, and true, so that we can allow our own actions to be a testimony. If we fail in this regard, then our actions cannot reveal what is done in secret by the disobedient for what they really are. We need to work together in this aspect. As a team works together with a common purpose to win the prize, we need to work together, encouraging each other, and keeping each other accountable to live as children of light. In so doing, the light that radiates from us can have its desired effect, to transform darkness into light.