Paul opens his letter to the Ephesians with an address to the Church. Then he defines two groups. One group he refers to as, us/we/our and the other group he refers to as
you/your. He includes himself in the first group, us/we/our. This group is the Jews. The context of verses 3-12 show this. Also verse 12 says, 'we who first trusted in Christ'. A more accurate translation would be, we who before hoped in the Christ. It was the Jews who had previously hoped in the Christ. Paul then contrasts this group with the you/your group and says they also, after they heard the word of truth, the Gospel. So one group had previously trusted in the Messiah and the other group trusted in the Messiah after they heard the Gospel. We know that the Jews had hoped in the Messiah for a long time, but after the Gospel the Gentiles too hoped in the Messiah. This shows us that the we/our/us group is the Jews and the you/your group is the Gentiles. However, if this isn't conclusive enough Paul states plainly that the you/your group is the Gentiles in chapter 2.
11 Therefore remember that
you, once Gentiles in the flesh-- who are called Uncircumcision by what is called the Circumcision made in the flesh by hands--
12 that at that time you were without Christ, being aliens from the commonwealth of Israel and strangers from the covenants of promise, having no hope and without God in the world. (Eph. 2:11-12 NKJ)
Here he refers to the "you" group as the Gentiles. The saints are the Jews. This can be seen further down in chapter 2.
14 For He Himself is our peace, who has made both one, and has broken down the middle wall of separation,
15 having abolished in His flesh the enmity, that is, the law of commandments contained in ordinances, so as to create in Himself one new man from the two, thus making peace,
16 and that He might reconcile them both to God in one body through the cross, thereby putting to death the enmity.
17 And He came and preached peace to you who were afar off and to those who were near.
18 For through Him we both have access by one Spirit to the Father.
19 Now, therefore, you are no longer strangers and foreigners, but fellow citizens with the saints and members of the household of God,
(Eph. 2:14-19 NKJ)
After stating that the "you/your" group were aliens to the convenants of promise, were far off, were without Christ and God, were without hope, he goes on to explain how the Gentiles, through Christ, have been brought near. Near to what? Those things that they were far from, the covenants, of promise, hope, Christ, and God. So, they were far off but have been brought near. In this section Paul is contrasting the Jews who were near and the Gentiles who were far off then he says this.
17 And He came and preached peace
to you who were afar off and to those who were near.
18 For through Him we both have access by one Spirit to the Father.
19 Now, therefore,
you are no longer strangers and foreigners, but fellow citizens with the saints and members of the household of God, (Eph. 2:17-19 NKJ)
Those who were far off, the Gentiles, are no longer strangers and foreigner but are "fellow citizens with the saints". The Gentiles were far off but are now fellow citizens with the Jews. They now are a part of the covenants of promise made to Israel, they now have hope, Christ, and God.
This is a quick overview. If you'd like a more in depth look at it you can read my commentary on the passage,
Ephesians 1