Verse 15: “In the hand of the one speaking to me was a golden reed for measuring the city, its gates and its wall.”

Verse 16: “The city was laid out as a square, its length and its width. He measured the city with the measuring reed, it was 12 000 furlongs. Its length, its width and its height were equal.” (a cube)

Verse 17: “And he measured the wall and it was 144 cubits, this is the measuring of a man. Which is also the measuring of the angel.”

One interpretation of this is that, in the Kingdom of God, humans and angels are going to have the same perspective.

Verse 18: “The construction of the walls were jasper stone; the city was fine gold, similar to pure glass.”

Verse 19: “The foundations of the wall of the city were adorned with every type of desirable stones: The first foundation was jasper, the second was sapphire, the third was וֹב֖שְׁ , the fourth was emerald.”

Verse 20: “The fifth was diamond, the sixth was דםֶ אֹ֤ , the seventh was שישִׁ֥ רְׁ תַּ , the eighth was “ַ.אחְׁ לָּ ָֽמָּ ה was twelfth the and ִֶׁ֥ל ֶשם was eleventh the ִׁ֥,נ ֶפְך tenth the ,פ טְׁ דָּ ה ֙ was ninth the , ֖ש ַּהם

These stones (We don’t know with certainty what kind they were) were all on the breastplate of the high priest. Each stone was connected to one of the twelve tribes of Israel. Israel is at the foundation of the plans, will and purpose of God. 

The foundations of the walls are the teachings of the apostles. The foundations (believers) support Israel (Like the centurion in Luke 7v4-5, we need to be concerned about the spiritual condition of Israel).

Verse 21: “The twelve gates, they were twelve pearls. Every gate was one pearl. The street of the city was fine gold. Like clear glass.”

Verse 22: “I did not see a temple in it (the city) for the Lord God of Hosts He and the Lamb are its temple.”

One of the key elements of the temple is the altar. There will be no sin, so there is no longer any need for sacrifice. Yeshua paid the price, fully, for all sin. In the New Jerusalem there is a state of eternal perfection.

Verse 23: “The city did not have any light of the sun, nor did the moon shine, for the glory of God illuminates it and the Lamb is its light.”

Verse 24: “And the nations that were saved will walk in its light. The kings of the earth will bring their glory and their splendor unto it.”

Everything that had made them great had nothing to do with this world. Real greatness and glory led to the Kingdom of God. They wanted to use their lives for the exaltation of the character/likeness of the Kingdom of God.

Verse 25: “The gates will not be closed in the day, for there will be no night there.”

The gates are open at all times, perfect security.

Verse 26: “And they would bring into it the glory of the nations, and their splendor.”

Verse 27: “All who are unclean, do abomination and lie shall not enter into it, rather the ones written in the Lamb’s Book of Life.”

The only way that we can enter into the New Jerusalem is if our names are written in the Lamb’s Book of Life. Unless we have accepted the blood of the Lamb for our redemption we are not going to be in that glorious Kingdom.