9 Then one of the seven angels who had the seven bowls full of the seven last plagues came and said to me, “Come, I will show you the bride, the wife of the Lamb.” 10 And in the spirit he carried me away to a great, high mountain and showed me the holy city Jerusalem coming down out of heaven from God. 11 It has the glory of God and a radiance like a very rare jewel, like jasper, clear as crystal. 12 It has a great, high wall with twelve gates, and at the gates twelve angels, and on the gates are inscribed the names of the twelve tribes of the Israelites; 13 on the east three gates, on the north three gates, on the south three gates, and on the west three gates. 14 And the wall of the city has twelve foundations, and on them are the twelve names of the twelve apostles of the Lamb.
15 The angel who talked to me had a measuring rod of gold to measure the city and its gates and walls. 16 The city lies foursquare, its length the same as its width; and he measured the city with his rod, fifteen hundred miles; its length and width and height are equal. 17 He also measured its wall, one hundred forty-four cubits by human measurement, which the angel was using. 18 The wall is built of jasper, while the city is pure gold, clear as glass. 19 The foundations of the wall of the city are adorned with every jewel; the first was jasper, the second sapphire, the third agate, the fourth emerald, 20 the fifth onyx, the sixth carnelian, the seventh chrysolite, the eighth beryl, the ninth topaz, the tenth chrysoprase, the eleventh jacinth, the twelfth amethyst. 21 And the twelve gates are twelve pearls, each of the gates is a single pearl, and the street of the city is pure gold, transparent as glass.
22 I saw no temple in the city, for its temple is the Lord God the Almighty and the Lamb. 23 And the city has no need of sun or moon to shine on it, for the glory of God is its light, and its lamp is the Lamb. 24 The nations will walk by its light, and the kings of the earth will bring their glory into it. 25 Its gates will never be shut by day—and there will be no night there. 26 People will bring into it the glory and the honor of the nations. 27 But nothing unclean will enter it, nor anyone who practices abomination or falsehood, but only those who are written in the Lamb’s book of life.
In these verses the writer shares his vision of the new Jerusalem as the bride of Christ descending out of heaven, made of precious jewels and shining like the sun, (though there is no sun or moon because it is lit by the light of God Himself). Quite a bit of detail goes into describing the jewels that are used to construct and adorn it, including some very specific measurements. The imagery is absolutely breathtaking, and it really impresses upon us the futility of trying to accumulate material treasure in this human life. Instead, we are encouraged to love our fellow humans and seek to help the less fortunate, because the treasures in heaven as described in this passage are beyond anything available to human beings on earth, even those who count themselves among the very richest.
The passage states that the gates of this new Jerusalem will never be shut, but that nothing unclean or sinful, (or any person who commits sin, or whose name is not written in the Lamb's book of life) will enter it. Interestingly there is no temple included in this setting, because to be in the presence of God is to be in a holy place, therefore there is no need to set apart any place within it as the entire city is holy and of God. I hope that everyone will accept Christ as Savior so that we will all get to see this bejeweled city and live with Christ and God forever.
A Prayer for Salvation from Christ:
Lord
Jesus, I confess my sins and ask for your forgiveness. Please come into
my heart as my Lord and Savior. Take complete control of my life and
help me to walk in Your footsteps daily by the power of the Holy Spirit.
Thank you Lord for saving me and for answering my prayer.
A more detailed step by step process:
https://www.wikihow.com/Accept-Jesus-Into-Your-Life