12 For it is shameful even to speak of those things which are done by them in secret.
“For” explains verse 11, which shows that the works of darkness of unbelievers need to be exposed by light.
it is shameful
To even speak of some things done in the dark carries a disgrace in itself.
even to speak of those things
Some things done by unbelievers in darkness are too shameful for Christians to speak about.
which are done by them in secret.
The emphasis of this verse is on the word “secret.” Those who walk in darkness admit that what they do is a disgrace to themselves before men. The words “in secret” give further degradation to “darkness.” Some sin is open and not in secret. Sexual sins are not generally done in public (except for the pornography and other such industries). Non-Christians normally like to hide their moral degeneracy.
Light reveals what darkness conceals.
Some talk among Christians carries disgrace in itself. These things are so vile that we should keep talk about them to a minimum. Nitroglycerin is so dangerous that to shake it will cause an explosion. Some things said among Christians will cause spiritual decline and disgrace.