Him who overcomes I will make a pillar in the temple of my God. Never again will he leave it. I will write on him the name of my God and the name of the city of my God, the new Jerusalem, which is coming down out of heaven from my God; and I will also write on him my new name.
Much of the book of Revelation is difficult to understand. As John saw visions of the future He saw an earth at least two thousand years from his time and often he would have been unable to accurately describe what he saw.
Likewise, we do not know how much of the book of Revelation is meant to be interpreted literally and how much of it should be understood as figurative. A good rule of thumb is to interpret the Bible as literal unless there is good reason not to. Even then, the book of Revelation is difficult to interpret.
One thing that is written about often though is a New Jerusalem. This will be a city unlike anything before. On earth Jerusalem was the place where David and his descendants ruled from. It was also the spiritual center where the temple was located.
But Jerusalem was subject to sin just as we are. The city was full of sinful people and was subject to judgment. In 586 BC the Babylonians carried away the inhabitants of the city. In AD 70 the Roman army set the city on fire. The temple burned and not one stone laid on top of another as the gold melted and ran between the cracks and soldiers pried the stones apart to retrieve the gold.
But there will be a new city that will be central for God’s people. It will not be subject to sin any longer. It will be incorruptible. It will be a city that is suitable for our worship of the Lord.