The city itself reflects the glory of Israel, Jesus, and the apostles, "the holy Jerusalem, descending out of heaven from God, Having the glory of God: and her light was like unto a stone most precious, even like a jasper stone, clear as crystal; And had a wall great and high, and had twelve gates, and at the gates twelve angels, and names written thereon, which are the names of the twelve tribes of the children of Israel: On the east three gates; on the north three gates; on the south three gates; and on the west three gates. And the wall of the city had twelve foundations, and in them the names of the twelve apostles of the Lamb." (Revelation 21:10-14). The perfect dimensions of the city reflect its divine nature, "he that talked with me had a golden reed to measure the city, and the gates thereof, and the wall thereof. And the city lieth foursquare, and the length is as large as the breadth: and he measured the city with the reed, twelve thousand furlongs. The length and the breadth and the height of it are equal. And he measured the wall thereof, an hundred and forty and four cubits, according to the measure of a man, that is, of the angel" (Revelation 21:15-17); as do the materials of the city, "the building of the wall of it was of jasper: and the city was pure gold, like unto clear glass. And the foundations of the wall of the city were garnished with all manner of precious stones. The first foundation was jasper; the second, sapphire; the third, a chalcedony; the fourth, an emerald; The fifth, sardonyx; the sixth, sardius; the seventh, chrysolyte; the eighth, beryl; the ninth, a topaz; the tenth, a chrysoprasus; the eleventh, a jacinth; the twelfth, an amethyst. And the twelve gates were twelve pearls: every several gate was of one pearl: and the street of the city was pure gold, as it were transparent glass" (Revelation 21:18-21). The presence of God precludes there being any temple therein, "And I saw no temple therein: for the Lord God Almighty and the Lamb are the temple of it" (Revelation 21:22) for a temple there would only serve to distract people from focusing on God--Why go to a temple, when God is at hand?
The city lies open to all travelers, " And the gates of it shall not be shut at all by day: for there shall be no night there" (Revelation 21:25). and, much unlike the present Jerusalem, there is no fear of vandalism, terrorism, or crime there "And there shall in no wise enter into it any thing that defileth, neither whatsoever worketh abomination, or maketh a lie: but they which are written in the Lamb's book of life" (Revelation 21:27). The word of God is sufficient to protect the city. Those who would enter it with evil intentions will find their efforts in vain, although there will be no apparent cause for their failure.
The clause, "there was no more sea" (Revelation 21:1) probably refers to the changes in the face of the Earth, and may refer to the absence of a specific body of water (for example, the Mediterranean Sea) but does not mean that there are no seas at all, "Then God said, 'Let the waters below the heavens be gathered into one place and let the dry land appear' and so it was. God called the dry land 'Earth' and the assembled waters 'seas'. And God said, that it was good" (Genesis 1:9-11). Similarly "And the city had no need of the sun, neither of the moon, to shine in it: for the glory of God did lighten it, and the Lamb is the light thereof" (Revelation 21:23) and "for there shall be no night there" (Revelation 21:25) do not mean that the Sun and the Moon do not shine in Heaven, but are metaphors used to express the greatness of God. And indeed, having "no need of the sun, neither of the moon" is not the same as not having them at all, for a flooded land has no need of rain, but this does not stop it from getting more.
This chapter also includes many clues that God has, as we say, 'a human shape' although Genesis makes it clear that it is we who have his, "God created man in his image" (Genesis 1:27). One example is found in Revelation 21:3, "the tabernacle of God is with men, and he will dwell with them, and they shall be his people, and God himself shall be with them, and be their God" where it is clear that God will mingle with men. The Lord God is meant by, "He that sat upon the throne" (Revelation 21:5) as is made clear when He says, "It is done. I am Alpha and Omega, the beginning and the end. I will give unto him that is athirst of the fountain of the water of life freely. He that overcometh shall inherit all things; and I will be his God, and he shall be my son" (Revelation 21:6-7). Sitting on a throne, however, requires a human-like shape. The promised relationship with God, "he shall be my son" also indicates a human-like shape.
We also get indications of this through the 'angel' who measures the city, "he measured the wall thereof, an hundred and forty and four cubits, according to the measure of a man, that is, of the angel" (Revelation 21:17). This indicates that the angel's dimensions correspond to human dimensions. But who is this angel? At Revelation 21:9 we are told, "there came unto me one of the seven angels which had the seven vials full of the seven last plagues". This same 'angel' continues to show St. John the city through chapter 22 where he says, "Behold, I come quickly" (Revelation 22:7) and "And, behold, I come quickly; and my reward is with me, to give every man according as his work shall be. I am Alpha and Omega, the beginning and the end, the first and the last" (Revelation 22:12-13) and finally, "I, Jesus, have sent mine angel to testify unto you these things in the churches. I am the root and the offspring of David, and the bright and morning star" (Revelation 22:16). So the 'angel' is Jesus himself, and he has human form.
The promise that God makes, "He
that overcometh shall inherit all things; and I will be his God, and he
shall be my son" (Revelation 21:7) applies most directly
to Christ, but it also applies to everyone. What must be overcome are the
temptations that lead one to place something other than God as the number
one priority in one's life. Being made God's son is metaphorical language
for the intimate relationship one will share with God. The language is
not meant to be sexist, but results from the fact that in the Greek and
Roman culture of St. John's day, sons were held in much higher esteem by
their fathers than daughters were, so promising to treat one as a daughter
would not have been much of a promise. The promise is meant to include
women, and to offer them an equal status with men by including them in
the same term. Of course, what that relationship with God actually turns
out to be will vary not only between men and women, but also from one individual
to the next.