In Genesis 1 and 2, we are told that God created the heavens and the earth with man as the center. Zechariah 12:1 says that God stretched forth the heavens, laid the foundation of the earth, and formed the spirit of man within him. The heavens, the earth, and man are the three basic and outstanding elements of the entire universe. Then at the end of the Bible, in Revelation 21 and 22, we see the new heaven, the new earth, and the New Jerusalem. The new heaven is to replace the old heaven, the new earth is to replace the old earth, and the New Jerusalem as the consummation of the new man is to replace the old man.
The old heaven and old earth will be baptized through fire and will pass away to become the new heaven and new earth (2 Pet. 3:10-13), into which the New Jerusalem will come to be God's eternal expression. The book of Matthew speaks of three kinds of baptisms: the baptism of water by John the Baptist, of Spirit by the Lord Jesus, and of fire, the lake of fire, by the Lord Jesus, not as the Savior but as the Judge (3:11). Eventually, everything will go through fire. Peter tells us in his second Epistle that the elements in the universe will be baptized in fire. After going through fire, the old heaven and old earth will come out to be the new heaven and new earth. This is similar to our baptism. We were the old man, but after passing through baptism, we become the new man. Thus, the new heaven replaces the old heaven, the new earth replaces the old earth, and the new man replaces the old man. This new man, the new creation, eventually and consummately is the New Jerusalem. The New Jerusalem is a new man.
Paul says in Galatians 6:15 that circumcision or uncircumcision means nothing; what matters is the new creation. The New Jerusalem will be the aggregate of God's new creation, and the new creation in the New Testament is also called the new man (Eph. 2:15; Col. 3:10). Eventually, the ultimate consummation of the corporate new man is the New Jerusalem. At the beginning of the Bible, the heavens, the earth, and man are old, but at the end they all become newthe new heaven, the new earth, and the new man, who is the new creation, the New Jerusalem.
Now we need to consider how the old man can become the new man. How could the first man Adam in Genesis 1 and 2 become a corporate New Jerusalem in Revelation 21 and 22? The Bible shows us that God has two kinds of creations: the old creation and the new creation. God completed His work of the old creation with the heavens, the earth, and man in the first two chapters of Genesis. Then in Genesis 3 Satan came in to inject himself into God's creation, to contaminate God's creation. So beginning from chapter three of Genesis, the entire old creation of God became corrupted, contaminated, and fallen. This fallen creation needs to be redeemed.
However, the Bible shows that God's eternal purpose is not just to redeem, to bring back, to repossess, the fallen old creation, but to regenerate man to make him the new creation. God's new creation work started from the second half of chapter three of Genesis. Man became contaminated and fallen, and in his fallen situation he did not know what to do. Then God came in to preach the gospel to Adam. The first gospel preaching was by God Himself to Adam in Genesis 3 on the seed of the woman (v. 15). The seed of the woman is Christ in the New Testament. Christ as the seed of woman would come to redeem, to restore man, and also to germinate, to regenerate, man (Gal. 4:4-6). Surely this is the work of the new creation, so from Genesis 3 the work of God's new creation begins.