4 According as he hath chosen us in him before the foundation of the world, that we should be holy and without blame before him in love:
When a sentence starts off with a word like according to, for, therefore, or because of, you have to go back to the previous verse(s) to find the subject. In this case, verses 1-3 are referring to the purpose of God the Father. Paul is going to start an amazing list of blessings that can only be found in Christ. According to God’s purpose, we have been chosen in Christ before the foundation of the world, holy and without blame before him.
Raise your hand if you see yourself as holy and blameless. Even when (not if) your life gets ugly, unholy and completely full of blame, believe God when he says this about you because he’s looking at Jesus who is holy and blameless! Our sin never hinders God’s purpose. When God purposed in his heart before the world began that he would save mankind through the death and resurrection of his son, causing all who believed in him to be holy and blameless before him in love, it was a done deal. (Col 1:22, 27-28, Eph 5:27, 2Th 2:13) That’s amazing grace!
5 Having predestinated us unto the adoption of children by Jesus Christ to himself,
According to God’s gracious will, if you are in Christ you were predestinated and predetermined to be in Christ as adopted children. Adam was created in God’s image, but after he sinned all of his descendants were born in Adam’s own likeness, not God’s, (Gen 5:3), therefore the rest of us were not automatically made children of God. Humanity was separated from God and were enemies of God (Col 1:21, Rom 5:10). Thankfully, if you are in Christ, through God’s grace, by faith apart from works, you are no longer an enemy but a true child of God!
By the way, did you know that Gentiles were never called God’s children? Only Israel was promised that position in God’s earthly plan as his chosen people. How then do we get adopted and become children of God? By faith in his son! (Rom 8:15, Gal 3:26). Not because we’re Israel, not through a covenant, or promise, and not because of works (Eph 2:8-9). We are children of God by grace, through faith in the finished work of Jesus Christ, (Rom 3:24-25). Without faith in Christ, you’re simply not a child of God, (Rom 8:9)
according to the good pleasure of his will,
What is God’s will? As we study Ephesians, and other scripture, we’re going to learn what that is. A good starting point is 1 Tim 2:3-4 “For this is good and acceptable in the sight of God our Saviour; 4 Who will have all men to be saved, and to come unto the knowledge of the truth.” That’s pretty self-explanatory. God wants all men to be saved in this dispensation! Part of our role as the body of Christ is to help make all men see what is the fellowship of the mystery of Christ which is our salvation by grace through faith, (Eph 3:9). We can positively know his will because he’s made it known, (Eph 1:9). Paul says you are unwise if you do not know it (Eph 5:17). Giving thanks to God for everything is another example of his will for our lives, (1 Thess 5:18).
6 To the praise of the glory of his grace, wherein he hath made us accepted in the beloved.
It doesn’t say ‘to the praise and glory…’, but ‘to the praise OF THE GLORY of his grace…’ True Biblical worship is our service to God according to his purpose, his will. His purpose is to save humanity by believing in Christ’s finished work on the cross, ultimately, magnifying the worth of God and his grace through faith in him. This is how we stand accepted in Christ.