1 And he has revived you, who were dead in trespasses and sins, 2 In which in time past you walked according to the course of this world, according to the prince of the power of the air, the spirit who now works in the children of disobedience, 3 Among whom also we all had our manner of life in times past in the lusts of our flesh, fulfilling the desires of the flesh and of the mind and were by nature the children of wrath, even as others. 4 But God, who is rich in mercy, for his great love with which he loved us, 5 Even when we were dead in sins, has made us alive together with Christ (by grace you are saved), 6 And has raised us up together and made us sit together in heavenly places in Christ Jesus, 7 So that in the ages to come he might show the exceeding riches of his grace in his kindness toward us through Christ Jesus. 8 For by grace you are saved through faith, and that not of yourselves. It is the gift of God. 9 It is not by works, lest any man should boast. 10 For we are his workmanship, created in Christ Jesus to good works, which God has before ordained that we should walk in them.
11 Therefore, remember, that you, being in time past Gentiles in the flesh, who are called Uncircumcision by that which is called the Circumcision in the flesh made by hands, 12 At that time you were without Christ, being foreigners from the commonwealth of Israel and strangers from the covenants of promise, having no hope and without God in the world. 13 But now in Christ Jesus you who formerly were far off are made near by the blood of Christ. 14 For he is our peace, who has made both one and has broken down the middle wall of partition between us, 15 Having abolished in his flesh the enmity, even the law of commandments contained in ordinances, to make in himself one new man of the two, so making peace, 16 And that he might reconcile both to God in one body by the cross, having by it slain the enmity, 17 And came and preached "peace to you who were afar off and to those who were near." 18 For through him we both have an access by one Spirit to the Father. 19 Now therefore, you are no longer strangers and foreigners, but fellow-citizens with the saints and of the household of God, 20 And are built upon the foundation of the apostles and prophets, Jesus Christ himself being the chief corner-stone, 21 In whom all the building properly framed together grows to a holy temple in the Lord, 22 In whom you also are built together for a habitation of God through the Spirit.
[v.8] - "and that not of yourselves" - In other words, "and this is not of your own doing, actions, or intentions." Grace is completely a free gift from God. It is given solely at God's discretion. We can do nothing to merit this favor.
[v.12] - Reference, Colossians 1:21.
[v.15] - "one new man" - In other words, a new humanity. Paul is speaking of Christians who are at peace with each other in Christ. Jesus, by the shedding of His blood, broke down the barrier between the Jews and the Gentiles, allowing them to unite together in Him.
[v.17] - Quoting Isaiah 57:19 (LXX—paraphrased).