First, the chief characteristic of God, which governs all other characteristics of God, is holiness. Unrighteous men and women can never enter into the presence of the righteous God. We must be as holy as God is. Christ is that way by which we are accepted by God. By His life and death He presented us to the Father holy and without blame. For by one offering He hath perfected forever them that are sanctified. There is no other way we can approach God other than in Christ. In Him the elect of God shall be called, the holy people.
Secondly, the sons of God shall be called the redeemed. The definition of redeem is to buy again something that has been sold, by paying back the price to him that bought it. On the cross there was a transaction made between God and Christ Jesus. Who was being bought? The people that God gave to Christ from the foundation of the world that was sold under the sin of Adam. Christ came to buy them back. What was the price? Gods justice must be satisfied. Transgression must be judged for Him to remain Just. Was the price paid? The shed blood of Gods perfect Lamb. Christ Jesus paid in full the price demanded. Gods justice is satisfied toward all those for whom Christ died. Now that the justice of God as been met, by that same characteristic of holiness, no judgement can come upon those brethren. Payment can not be made twice. Christ now owns a possession and none will be lost for they cost too much to be lost. So then the daughter of Zion shall be called the redeemed of the Lord.
In addition, the redeemed of the Lord shall also be called sought out. His name is Jesus for He shall save His people. He came to seek and to save that which was lost. I will put my laws into their hearts, and in their minds will I write them; And their sins and iniquities will I remember no more. Now where remission of these is there is no more offering for sin. A man that has been made holy, a man that has been redeemed, by the person and work of Jesus Christ, must be sought out and brought into the sheepfold else God is unjust in that He counts Christs sacrifice as nothing. Therefore, by the work of the Holy Spirit, every one for whom Christ made holy and redeemed will be sought out.
Finally, this city will not be forsaken. These are the words of the Lord, to the religious Jews during His earthly ministry Ye believe not because ye are not of my sheep, as I said unto you. My sheep hear my voice, and I know them, and they follow me: And I give unto them eternal life; and they shall never perish, neither shall any man pluck them out of my hand. My Father which gave them to me is greater than all and no man is able to pluck them out of my Fathers hand. The citizens who make up Zion shall be both Jew and Gentile. All shall have this in common: elected unto salvation by God Almighty, made holy and redeemed by the person and work of the Lord Jesus Christ, sought out and not forsaken but kept by the power of God through the Holy Spirit. Every one for whom Christ died shall populate the city of Zion and that city shall never be forsaken.