Having lost all sensitivity, they have given themselves over to sensuality so as to indulge in every kind of impurity, with a continual lust for more (Ephesians 4:19)
Paul tells the Ephesian Christians that they must no longer live as the Gentiles do. What is Paul talking about? Who are these Gentiles?
Sure, Paul might be talking to a gathering of people made up of both ethnic Jews and Greeks. Paul, however, means something different than race when he uses the term Gentile here. In his letter to the Galatians, Paul made it clear that neither ethnicity, bloodline, social standing, nor anything else mattered where God was concerned. Faith in Christ is what makes a child of Abraham. Faith is what takes hold of God's promise of the forgiveness of sins in Christ.
So, who is he talking about, then?
He describes the Gentiles as futile in their thinking. He says they are darkened in their understanding. They are separated from the life of God because of their ignorance. Their hearts are hardened. The result of this situation is that their condition is manifest in how they live. They are given over to sins of the flesh with a continual lust for more. One gets the impression from Paul's writing here that this appetite for sensual sins is meant to be understood as unquenchable.
In short, they are people who are not Christians.
He also talks about this in his letter to the Romans. At the beginning of that letter, Paul describes how mankind rejected God and was given over to sinful desires, shameful lusts, and ultimately to a depraved mind. Paul writes, "Although they know God's righteous decree that those who do such things deserve death, they not only continue to do these very things but also approve of those who practice them" (Rom. 1:32).
The more things change, the more they stay the same. Location, language, culture, technology, and time might separate us from the Ephesians of the Roman Empire, but our culture is just as depraved as theirs seems to have been. The reason: their society, just like our society, was filled with fallen sinful human beings, living in a fallen creation.
Paul calls us out of the world just as he called the Ephesians to come out. He calls us to put off the old way of life and put on the new man. The old man is corrupted by deceitful desires. The new man is created to be like God in true righteousness and holiness. Paul says to be made new in the attitude of our minds. How do we do that?
This is not a command for us to do so that we become better Christians. It is not a positive affirmation. It's more like Jesus' command to Lazarus to rise from the dead and come out from the tomb. The Word of God is the very thing that brings about the new attitude, just as it was efficacious to raise the dead. It is this renewing of the mind that transforms one into the new man who does not conform to the pattern of the world.
Ultimately, Paul is calling the Ephesians, and us all, to repentance. That is the concept behind his imperative "to be made new in the attitude of your minds." He's talking about a change of heart and life that is affected in us by God's Holy Spirit working through the Word.