B1 NKJV: This I say, therefore, and testify in the Lord, that you should no longer walk as the rest of the Gentiles walk, in the futility of their mind, having their understanding darkened, being alienated from the life of God, because of the ignorance that is in them, because of the blindness of their heart; who, being past feeling, have given themselves over to lewdness, to work all uncleanness with greediness. But you have not so learned Christ, if indeed you have heard Him and have been taught by Him, as the truth is in Jesus: that you put off, concerning your former conduct, the old man which grows corrupt according to the deceitful lusts, and be renewed in the spirit of your mind, (Ephesians 4:17-23)
B2 WEL:  Therefore I speak this and bear witness in the Lord, that from now on you walk not like other Gentiles walk in the emptiness of their mind.  Having their understanding darkened, being alienated from the life of God through the ignorance that is in them, because of the blindness of their heart.  Who being callous gave themselves over to lustful pleasure to do every kind of impurity with insatiable desire.  But you haven't learned Christ in this way.  If you learned Him and been taught by Him, then, as the truth is in Jesus,  Get rid of the former lifestyle, the old man, which is rotten from deceitful lusts.  Instead be renewed in the spirit of your mind. (Ephesians 4:17-23
B3 GNB: In the Lord's name, then, I warn you: do not continue to live like the heathen, whose thoughts are worthless and whose minds are in the dark. They have no part in the life that God gives, for they are completely ignorant and stubborn. They have lost all feeling of shame; they give themselves over to vice and do all sorts of indecent things without restraint. That was not what you learned about Christ! You certainly heard about him, and as his followers you were taught the truth that is in Jesus. So get rid of your old self, which made you live as you used to—-the old self that was being destroyed by its deceitful desires. Your hearts and minds must be made completely new, (Ephesians 4:17-23)
B1 Lifestyle and Worldview
C1 Gentiles (unsaved)
D1 Futility of their mind
D2 Understanding is darkened
D3 Alienated from the life of God
D4 All the above from ignorance
E1 Blindness of heart
E3 Addicted to fleshly pleasures―impurity of all sorts
C2 Gentiles (saved)
D1 Jesus is THE teacher
E1 We are the learners
E2 He the teacher
E3 Jesus tells the truth
C3 The old lifestyle must go, disappear, not be followed anymore, forsaken
D1 Because it is the "old man."
D2 It is rotten.
D3 All from deceitful lusts.
C4 We are to be renewed in the spirit of our mind
C1 Gentiles: non-Israelites (Jews)
C2 Futility of their mind = the mind is our thinking ability, the place where we think. Futility is emptiness, non-thinking ability, "being stupid," etc. Futility is the idea of having no truth, sense of truth, interest in the truth, so that when truth comes along, it is suppressed ("For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who suppress the truth in unrighteousness" (Romans 1:18 NKJV). It takes the Holy Spirit's initiative and action to open our minds and hearts to the truth.
C3 Understanding is darkened = understanding is comprehension, the ability to "catch on" to something. The idea of choices have consequences is not foreseen, and so they (we) make stupid choices that lead to unintended, perhaps consequences that are difficult, life threatening, death, pain in ourselves or others. Darkened because God's ways and thoughts are not present in us. When and if we hear about God and His ways, our unregenerate heart rebels and rejects it unless the Holy Spirit opens our hearts and minds.
C4 Alienated from the life of God = we are under God's curse because of our sin and the sin of the world. We are separated from God and doomed to destruction.
C5 Blindness of heart = What causes all this is humanity's ignorance from a blind heart (a heart that cannot see, understand, know God and His ways), callousness from sinning and suppressing the guilt (justifying ourselves), and addicted to pleasing our various and sundry desires. Sin is very addictive.
C6 The saved Gentiles are different because of Jesus teaching, the Holy Spirit's conviction of our heart, and opening the way to trust into Jesus Christ.
C7 Because we are now new creations, we must live that way. The Bible has the means and rules to do this. The Holy Spirit is our helper, encourager, prodder, rebuker (when needed) to keep going.
B2 Questions and applications
C1 How are you living your life in thoughts, desires, words, and deeds?
C2 Is there a difference in our lives now that we are Christians? Is this something that others can see? Matthew 5:14-16 HCSB You are the light of the world. A city situated on a hill cannot be hidden. No one lights a lamp and puts it under a basket, but rather on a lampstand, and it gives light for all who are in the house. In the same way, let your light shine before men, so that they may see your good works and give glory to your Father in heaven.
C3 Before the outpouring of the Holy Spirit humanity was divided into Jews or Gentiles. Now it is Jews, Gentiles, and Church. The church are all those who believe and trust in Messiah Yeshua for salvation, forgiveness of sins, and restored fellowship with God.
C4 We need reminders from each other and the Scriptures to keep faithful to New Testament doctrine and life. We should be teaching each other, praying for each other, encouraging each other, and reading/studying the Bible each and every day.
C5 A few of the rules that the Lord Jesus has given us in the New Testament: 1 Thessalonians 5:14-26 NRSV And we urge you, beloved, to admonish the idlers, encourage the fainthearted, help the weak, be patient with all of them. 15 See that none of you repays evil for evil, but always seek to do good to one another and to all. 16 Rejoice always, 17 pray without ceasing, 18 give thanks in all circumstances; for this is the will of God in Christ Jesus for you. 19 Do not quench the Spirit. 20 Do not despise the words of prophets, 21 but test everything; hold fast to what is good; 22 abstain from every form of evil. 23 May the God of peace himself sanctify you entirely; and may your spirit and soul and body be kept sound and blameless at the coming of our Lord Jesus Christ. 24 The one who calls you is faithful, and he will do this. 25 Beloved, pray for us. 26 Greet all the brothers and sisters with a holy kiss. (Emphasis is mine).