Probably one of the most common problems we face when studying a NT epistle is our desire to "skip ahead" to the "Application" portion of the letter before we have had an opportunity to seriously reflect upon the earlier "Doctrinal" portion which undergirds even the possibility of "Application." As a result we become heavily focused upon "doing" without having a solid appreciation for the rhyme or reason, or the power behind it. Bypassing the doctrine results in a "morals-based" Christianity. We completely focus on the end-product, to the point that we begin to think we are getting "brownie points," "earning" God's favor for having "accomplished" some right behavior. Saved by the gospel, we now abandon its power and turn our focus completely onto ourselves, instead of onto the God who made our obedience even possible. We may even begin to expect that God "owes us," that we "deserve" blessings or at least "a break."
Ephesians 4-6 provides such a good example. In my early biblical counseling training, those three chapters provided a solid basis for Christian living. If you've ever taken "Self Confrontation," you're certainly familiar with the commands in these three chapters: "Be angry and sin not," "Be kind to one another, tenderhearted," "Speak the truth in love." And yet how many times have you heard people say, "I keep working on the same problem!" They know these verses, they try to obey them ... but they continually fail. And what is the eventual result? They might "give up," perhaps contenting themselves in their sin. Or they may concentrate instead on verses that are easier for them to consistently obey, building a foundation of spiritual pride. Or they might conclude, "That's hard." and try to ignore the command. Or even worse, they might say, "I tried that and it didn't work."
It's tragic! Now let's bring in the context. Go back to Eph. 4:1. What KEY connecting word do you see at the very start? You're right... it's "therefore." What does that tell you? Right again... what follows is a RESULT of the truth that has just been written. And what HAS just been written in Chapters 1-3? That's right... it's "doctrine." [You're really good at answering these questions!]
Paul has spent the first 3 chapters explaining what God has done for believers, those who "were dead in trespasses and sins." God "chose" them "before the foundation of the world", He "predestined" them "for ADOPTION as sons through Christ Jesus", He "LAVISHED the riches of His grace" upon them, He "BLESSED them in Christ with EVERY spiritual blessing" ... and so on ... and so on. Stop! Think about these truths, chew on them, reread Eph.1-3 every day for a week and ruminate on truths revealed! Let them seep down in deep, ponder them, think about their implication. Then, and only then, move on to Eph. 4:1... "THEREFORE ... "
Do you see those last three chapters a little differently now? If you truly comprehend the doctrine in Chapters 1-3, then your heart's desire is to respond in obedience. Don't ever separate the doctrine of the early chapters from the commands in the final chapters, or you'll become "morals-driven" and destined for failure, instead of "gospel-driven" and destined to glorify the God who has shed His mercy on you.