What does Ephesians 4:19 mean?

Three additional drawbacks to the life of unbelievers are provided in this verse, in addition to the two given in verse 18. First, "They have become callous." Used only here in the Bible, the meaning of "calloused" is that of becoming numb and desensitized to sin. Unbelievers can do what is wrong and have little or no conviction of wrongdoing.

Second, unbelievers have put themselves under the control of their sexual urges. This reference to sexual immorality is general and could include a variety of practices. Paul uses the Greek term paredōkan, which implies someone handed over to the power of another, betrayed, or captured. Sin is not only destructive, it is addictive. Saddest of all, the brutal oppression of sin is something we inflict on ourselves: we "give ourselves up" to it.

Third, unbelievers seem eager to push the limits of human depravity. Paul uses this phrase as a general description, rather than making a longer, more specific list of sins. This is evident due to the transition he makes in the next verse, "but," in order to remind believers that this is not how they are to live. Paul often spoke of impurity as displeasing to God (Romans 1:24; 6:19; 2 Corinthians 12:21; Galatians 5:19; Colossians 3:5; 1 Thessalonians 2:3; 4:7).