When one gets to Ephesians 4:1-16 and throughout the final chapters of the letter we read the practical suggestions that are proposed to the early church. These practical matters are preceded in the first three chapters by much more theologically argued discourse. Beginning in chapter 4 it seems Paul or whoever passed on his thoughts in the letter is following the advice given by a student to William Sloan Coffin (1924-2006), "...when you say something that is both true and painful, say it softly." In other words, say it to heal and not to hurt.
Almost anyone who has read Paul's letters is aware how he often seems to speak truth regarding some pretty painful matters going on in the early house churches. And, one may wonder if Paul is speaking so softly as he from time to time addresses these early Christians regarding true and painful issues (such as all the friction in these communities).
As you read Ephesians think about what we read elsewhere about Paul. As one interpreter speaks about Paul we see a quite complex, multifaceted but dedicated, helping and healing individual.
"He spoke in tongues (1 Cor. 14:18). He experienced celestial visions in which he believed he had been transported to the heavenly realm (2 Cor. 12:1–7). He received revelations from the Lord (Gal. 2:2) and sometimes expected people to regard his rulings on matters as bearing the mark of divine authority (1 Cor. 14:37–38; cf. 7:12, 39–40). He was a man who prayed much (Rom. 1:9; 1 Thess. 1:2–3; 3:10), sometimes with troubled longing (Rom. 8:26), but often with joyful praise (Phil. 1:3–4). He is often given to unabashed displays of emotion and sentiment (2 Cor. 2:4; Phil. 3:18), speaking openly of his affection for those who are dear to him (2 Cor. 7:2–4; Gal. 4:19–20; Phil. 4:1; 1 Thess. 2:17–20; Philem. 4–7). But he can also be roused to anger and is not shy about expressing that emotion either (1 Cor. 4:19–21; 2 Cor. 11:12–15; Gal. 1:9; 3:1; 5:12). At times Paul seems to embody a confident faith that many would regard as idealistic (Phil. 4:11–13), but at other times he seems remarkably down-to-earth, recognizing a need for dealing with practical concerns in a realistic manner (1 Cor. 7:3–5).
At times Paul can seem to be a morass of contradictions. He can seem a champion of women’s rights in one instance (Rom. 16:1–2) and a proponent of patriarchal chauvinism in another (1 Cor. 11:1–16). At one point, he seems to question the validity of all human authority figures (Gal. 2:6), but elsewhere he commends his readers to show respect for those who are over them in the Lord (1 Thess. 5:12–13)—and even to be subject to pagan political rulers, since all authorities have been instituted by God (Rom. 13:1–7). He can adopt a tolerant “agree to disagree” attitude on some controversial issues (Rom. 12:5), but he seeks to lay down the law in an absolute sense on other matters (1 Cor. 7:17; 11:16; 14:33–36). He is capable both of commending gentleness (Gal. 5:23; 6:1; Phil. 4:5) and of threatening people with harsh discipline (1 Cor. 4:21; 5:1–5; 2 Cor. 13:2). He emphasizes grace and forgiveness, but insists that people reap what they sow (Gal. 6:6–10) and says that wrongdoers will not inherit the kingdom of God (1 Cor. 6:9). Unless such seeming inconsistencies are recognized, any understanding of Paul may be one-sided or incomplete."
Mark Allan Powell, “Paul,” ed. Mark Allan Powell, The HarperCollins Bible Dictionary (Revised and Updated) (New York: HarperCollins, 2011), 762.