Rev 21:1-27

A NEW HEAVEN AND EARTH
1 I saw a new heaven and a new earth: for the first heaven and the first earth have passed away, and the sea is no more. 
Rev 21:1
A New Heaven and a new earth – after the judgment Day, described in Revelation Chapter 20, we shall enter the new heaven and new earth, prophesied by Isaiah:

“For behold, I create new heavens and a new earth;
And the former shall not be remembered or come to mind.
But be glad and rejoice forever in what I create;
For behold, I create Jerusalem as a rejoicing,
And her people a joy.
I will rejoice in Jerusalem,
And joy in My people;
The voice of weeping shall no longer be heard in her,
Nor the voice of crying.
– No more shall an infant from there live but a few days,
Nor an old man who has not fulfilled his days;
For the child shall die one hundred years old,
But the sinner being one hundred years old shall be accursed.
..The wolf and the lamb shall feed together,
The lion shall eat straw like the ox.”

Isa 65:17-25

no longer sea – the meaning of “sea” from Rev 20:13, etc, is salvation. There is no longer a need for salvation after the judgment Day.
2 I saw the holy city, New Jerusalem, coming down out of heaven from God, made ready as a bride adorned for her husband. 
Rev 21:2
the holy City, new Jerusalem – to be described in verse 10-27
3 I heard a loud voice out of heaven saying, “Behold, God’s tent is with men, and he will dwell with them, and they will be his people, and God himself will be with them as their God. 
Rev 21:3
a loud voice from the throne – the voice of the Archangel, the Spirit of Christ, who speaks for the invisible God in verse 5. See also Rev 19:5, and Rev 19:10.

the tabernacle of God is among men – this can describe New Jerusalem, in heaven and earth, the holy City and the kingdom of God that began on earth. See also Rev 7:15.
4 He will wipe away every tear from their eyes. Death will be no more; neither will there be mourning, nor crying, nor pain, any more. The first things have passed away. 
Rev 21:4
He will wipe away every tear – see also Rev 7:17.
5 He who sits on the throne said, “Behold, I make all things new.” He said, “Write, for these words are faithful and true.” 
Rev 21:5
And He who sits on the throne – see also Rev 4:2, Rev 5:1, the Spirit of Christ, again, appears as the image of the invisible God on the throne.

Write, for these words are faithful and true – the Spirit of Christ, speaking as the Archangel, again asks John to “write.” See Rev 19:9 “Write…these are the true words of God.”
6 He said to me, “It is done! I am the Alpha and the Omega, the Beginning and the End. I will give freely to him who is thirsty from the spring of the water of life. 
Rev 21:6
It is done – also the words of the Archangel in Rev 16:17. God’s salvation plan is complete, the plan to conform man to the image of His Son (Rom 8:29); the plan that God expressed in the beginning of creation: “Let Us make man in Our image,” (Gen 1:26); “when we see Him, we shall be like Him,” (1 John 3:2;  1 Cor 13:12).

I am the Alpha and the Omega – the Spirit of Christ begins to speak as the Word, as He did in Rev 1. After the Lord’s Day, Christ will submit to God, and He will be God’s speaker, as in the Old Testament.
7 He who overcomes, I will give him these things. I will be his God, and he will be my son. 
Rev 21:7
he who overcomes – just as Christ overcame, see Rev 3:21, we will also become a Son of God. Christ, the Male Child, was the firstborn from the dead.

I will be His God – there is only one God, the Father (1 Cor 8:6; Eph 4:6).

he will be My Son – like Christ who became the first Son, when He resurrected (Acts 13:33).
8 But for the cowardly, unbelieving, sinners, abominable, murderers, sexually immoral, sorcerers, idolaters, and all liars, their part is in the lake that burns with fire and sulfur, which is the second death.” 
Rev 21:8
cowardly – or timid, fearful. The sin of cowardice is first mentioned here. John told us that “perfect love casts out fear” (1 John 4:18). Those who are victorious, are those who do not love their own lives, even to the death (Rev 12:11, John 12:25).
9 One of the seven angels who had the seven bowls, who were laden with the seven last plagues came, and he spoke with me, saying, “Come here. I will show you the wife, the Lamb’s bride.” 
Rev 21:9
one of the Angels with the seven bowls of wrath – the description is the same as Rev 17:1. This time, we are certain the Angel is the Spirit of Christ, because He speaks as Christ in Rev 22:7. As mentioned in Rev 16:17, it should likely be the seventh Angel, whose bowl was poured on the air and sounded a loud voice saying “It is done.”

Come, here, and I will show you the Lord’s wife… – the Angel of God continues to guide John, now to see the Lord’s wife, the sanctified Church, who was the bride of Christ, and is the now the wife of Christ; after purifying herself to become as a pure and spotless bride (Eph 5:27). See also Rev 19:7.
10 He carried me away in the Spirit to a great and high mountain, and shown me the holy city, Jerusalem, coming down out of heaven from God, 
Rev 21:10
carried me away in the Spirit – as in Rev 1:10, Rev 4:2; Rev 17:3, Ezek 11:1 etc.

a high mountain – the Sanctified Church as a mountain, see Isa 2:2, Mic 4:1-2, etc.

the holy City – described in Rev 11:2, Rev 12:1, and Rev 14:20.
11 having the glory of God. Her light was like a most precious stone, as if it was a jasper stone, clear as crystal; 
Rev 21:11
having the glory of God – this is the Church. It is the Spirit of Christ as the body of Christ, see Isa 6:3, John 1:14.

crystal clear Jasper – a red colour, and the clearness must signify the washing of the Church by the blood of Christ.
12 having a great and high wall; having twelve gates, and at the gates twelve angels; and names written on them, which are the names of the twelve tribes of the children of Israel. 13 On the east were three gates; and on the north three gates; and on the south three gates; and on the west three gates. 
Rev 21:12
twelve gates and twelve angels – these are the twelve stars in Rev 12:1. They have the names of the twelve tribes of Israel, see the eleven stars seen by Joseph in his dream of Gen 37:9.
14 The wall of the city had twelve foundations, and on them twelve names of the twelve Apostles of the Lamb. 
Rev 21:14
twelve foundation stones – the Church is built on the foundation of the Apostles, Eph 2:20.
15 He who spoke with me had for a measure a golden reed to measure the city, its gates, and its walls.
Rev 21:15
the one who spoke with me had a gold measuring rod – this is our first clue that the Angel speaking with John is the Spirit of Christ. The measuring rod was first seen in Ezek 40:3. The man of bronze, (Christ, Dan 10:6), who was called Yihvah in Ezek 44:2 – 5, and set the measurements of the Church with the Gospel. See also Rev 11:1.
16 The city lies foursquare, and its length is as great as its breadth. He measured the city with the reed, twelve thousand stadia. Its length, breadth, and height are equal.
Rev 21:16
as a square – all sides are equal, there is neither male nor female, Greek nor Jew.

fifteen hundred miles square – more than 3 times the size of Russia. The Greek word used is “stadia” from which we get “stadium.” It is 1/8 of a mile. Literally 12,000 stadia, or 1,500 miles.
17 He measured its wall, one hundred forty-four cubits, by the measure of a man, that is, of an angel. 
Rev 21:17
seventy two yards thick – literally, 144 cubits. A cubit is the length of a forearm, about 18 inches, giving us 72 yards. The walls of Ancient Babylon were 300 feet high, 25 feet thick with another wall 75 feet behind the first wall.
18 The construction of its wall was jasper. The city was pure gold, like pure glass. 
Rev 21:18
jasper walls – see Rev 21:11, the first layer of the foundation is also jasper. Presumably the first layer of the foundation of the house, is the only layer visible to the eye, as covered by the blood of Christ, red as jasper.
19 The foundations of the city’s wall were adorned with all kinds of precious stones. The first foundation was jasper; the second, sapphire; the third, chalcedony; the fourth, emerald; 20 the fifth, sardonyx; the sixth, sardius; the seventh, chrysolite; the eighth, beryl; the ninth, topaz; the tenth, chrysoprasus; the eleventh, jacinth; and the twelfth, amethyst. 
Rev 21:19
precious stones – which are the good works of the saints, see 1 Cor 3:12. On these stones are the names of the Apostles, these are listed according to the shade of colour.
21 The twelve gates were twelve pearls. Each one of the gates was made of one pearl. The street of the city was pure gold, like transparent glass. 
Rev 21:21
twelve pearls – the kingdom of heaven is called the pearl of great price, (Matt 13:45-46) which is now the gate.
22 I saw no temple in it, for the Lord God, the Almighty, and the Lamb, are its temple. 
Rev 21:22
no temple – in Rev 21:3, we read “now is the tabernacle of God is among men.” There is no more need for a temple.
23 The city has no need for the sun, neither of the moon, to shine, for the very glory of God illuminated it, and its lamp is the Lamb. 
Rev 21:23
no sun or moon – see Isa 60:19.
24 The nations will walk in its light. The kings of the earth bring their glory into it. 25 Its gates will in no way be shut by day (for there will be no night there), 
Rev 21:25
the gates will never be closed – see Isa 60:11.
26 and they will bring the glory and the honor of the nations into it. 27 There will in no way enter into it anything profane, or one who causes an abomination or a lie, but only those who are written in the Lamb’s book of life.
Rev 21:26
the nations will bring their glory in – see Isa 60:11.