Compare Ephesians 4:17-32 with Colossians 3:1-17. How does Paul advocate for believers to live in a way that encourages the unity of the church?

 In the prior section, Ephesians 4:1-16, Paul’s theme was the unity of the church. When we compare Ephesians 4:1 and Ephesians 4:17, we note how similar these two exhortations are about how to walk or to live. This resemblance suggests that Paul addresses the same theme — unity and the lifestyle that supports it — but from a new and initially more negative vantage point.

 In Ephesians 4:17-24, Paul contrasts Gentile lifestyle, which he regards as undermining unity (Eph. 4:17-19), with truly Christian patterns of life that nourish it (Eph. 4:20-24). As we read Paul’s sharp critique of the depraved, Gentile lifestyle, we should recall his conviction that Gentiles are redeemed by God through Christ and offered full partnership in the people of God (Eph. 2:11-22, Eph. 3:1-13). In Ephesians 4:17-19, then, he is offering a limited and negative description of “Gentiles in the flesh” (Eph. 2:11).

 Paul is not just concerned about specific sins or behaviors exhibited by Gentiles. He is concerned about a pattern of behavior that they exhibit, a downward trajectory of living in the grip of sin. At the heart of Ephesians 4:17-19 is a portrait of a calloused spirituality: “in the futility of their mind, having their understanding darkened, being alienated from the life of God” (Eph. 4:17, 18, NKJV). This calloused spirituality is the source of the darkened understanding highlighted at the beginning of the passage (“because of the ignorance that is in them, due to their hardness of heart. They have become callous,” Eph. 4:18, 19, ESV) and the depraved sexual practice underlined at its end (“and have given themselves up to sensuality, greedy to practice every kind of impurity,” Eph. 4:19, ESV). Alienated from God, they don’t know how to live, and, separated from His saving grace, they continue in a downward spiral of sin and depravity.