Summary: The beginning of this great epistle covers such grand bible themes as foreknowledge, predestination, God’s calling, redemption, forgiveness of sins, hearing the word of truth, and the seal of the Holy Spirit.
Ephesians 1:1-3 ... Praise be to the God and Father of our Lord Jesus Christ, who has blessed us in the heavenly realms with every spiritual blessing in Christ.
•• God is inclined to bless His children. It is His desire, His will, to bless us, not to leave us to struggle.
•• His most important blessings are “in the heavenly realms” — far more important than “earthly” blessings.
•• “...with every spiritual blessing” —
• “Every” suggests lots of blessings!
• And these are the highest kind — “spiritual” ones.
•• God’s blessings are to be found “in Christ”.
• John 1:16“From the fullness of [Jesus’]grace we have all received one blessing after another.”
1:4-6 For he chose us in him before the creation of the world to be holy and blameless in his sight. In love  he predestined us to be adopted as his sons through Jesus Christ, in accordance with his pleasure and will...
•• [vs. 4] “He chose us...before the creation.” There is a link between election and foreknowledge.
• Romans 8:29-30 For those God foreknew he also predestined to be conformed to the likeness of his son, that he might be the firstborn among many brothers.  And those he predestined, he also called; those he called, he also justified; those he justified, he also glorified.
• Notice the order of thought: “Those God foreknew he also predestined.... And those he predestined, he also called.”Foreknown —> predestined —> called.
• Theologians have debated predestination for centuries. The thing to remember as you ponder that great subject is that it begins with God’s perfect foreknowledge of things that will happen and decisions people will make.
•• [vs. 4] “He chose us ... to be holy and blameless.”
• Again, Romans 8:29 says that “God ... predestined [us] to be conformed to the likeness of his son.” That is a major emphasis of God’s predestination — that is, that we be conformed to Christ’s likeness. To summarize that, our predestination is unto Christlikeness, unto holiness and blamelessness (Ephesians 1:4).
•• [vs. 5] “He predestined us to be adopted as his sons.”
• Remember, though, it’s a predestination of “those God FOREKNEW”. This suggests to me a balance of God’s sovereignty and the free will that God has placed in man, a balance that includes and takes into account God’s foreknowledge of actions and choices that people of all ages will make.
1:7-8In him we have redemption through his blood, the forgiveness of sins, in accordance with the riches of God’s grace  that he lavished on us with all wisdom and understanding.
•• “Redemption...in Him [Christ]” — The Expositor’s Bible Commentary says: “Redemption has to do with the emancipation either of slaves or of prisoners.”
• Romans speaks several times of our being “slaves to sin”.
• Therefore, we need “the forgiveness of sins”. The Greek word for forgiveness means loosing a person from that which binds him. We need loosing and freedom from our sins. And that comes “in Christ”.
•• The cost, the price, for that redemption from our sins is found in the phrase “through his blood”. Jesus’ blood paid the price for our redemption.
• And, lest we ever forget, it comes “in accordance with the riches of God’s grace”.
• Ephesians 2:8-9 “It is by grace you have been saved, through faith ...  not by works...”
1:13-14 And you also were included in Christ when you heard the word of truth, the gospel of your salvation. Having believed, you were marked in him with a seal, the promised Holy Spirit,  who is a deposit guaranteeing our inheritance until the redemption of those who are God’s possession — to the praise of his glory.
•• “You also” = the Gentile believers (the Jews were spoken of in vs. 12).
•• How did they come to be “included in Christ”? The answer? — “They heard the word of truth, the gospel ... [and they] believed.”
• Take note of Hebrews 4:2, KJV“...the word preached did not profit them, not being mixed with faith in them that heard it.” To be saved and “included in Christ”, one must hear the word of truth and believe it.
•• These new converts were “marked in him with a seal, the promised Holy Spirit.”
• This sentence has received various interpretations, but it certainly includes the thought of John 20:22 — “[Jesus] breathed on them and said, ‘Receive the Holy Spirit.’" That is, their new birth by the Spirit, reminiscent of the creation of Adam in Genesis 2:7.