In the very first verse of Revelation 21 we are told the old covenant had passed away (Heaven and Earth). We know this is true and verse 4 verifies it. The first things (old order of things/former things) have passed away. This is clearly speaking of the end of the old covenant.

Verse 2 is the place that Jesus went and prepared for us (His Church, Kingdom, Body of Christ the New New Jerusalem). The New Jerusalem is the Bride of Christ. He [Christ] who has the bride [us Christians] is the bridegroom [Christ]... (John 3:29) See also (Matthew 22:1-14, 2 Corinthians 11:2, Ephesians 5:22-32, Revelation 19:7-8) Israel was the original bride of the LORD (Jeremiah 2:1). But she received divorce and punishment. The new bride the church (The Kingdom), came to take her place. Old Covenant Jerusalem is destroyed and replaced by the New Jerusalem of which first-century Christians were citizens.

Ephesians 2:18-22 for through Him we both have our access in one Spirit to the Father. 19 So then you are no longer strangers and foreigners, but you are fellow citizens with the saints, and are of God’s household, 20 having been built on the foundation of the apostles and prophets, Christ Jesus Himself being the cornerstone, 21 in whom the whole building, being fitted together, is growing into a holy temple in the Lord, 22 in whom you also are being built together into a dwelling of God in the Spirit. And in Hebrews 12:22 But you have come to Mount Zion and to the city of the living God, the heavenly Jerusalem, and to myriads of angels,

The foundations of the New Jerusalem are the "twelve apostles of the Lamb" (Revelation 21:14). Paul, in Ephesians 2:18-22,uses identical language about citizenship in the "household of God" as having been "built on the foundation of the apostles and prophets."

In Revelation 21:1-7 we see that The dwelling place of God is with man. He will dwell with them, and they will be his people. So, again, this is about the new covenant relationship with God's people, not a literal city or building. Nor is it about heaven, as some people think. How do we know this? Isaiah 65:20 and Revelation 22:15 tells us death will continue. In fact, killing still take while in the New Jerusalem. The gates are still open to this very day. And always will be.

Outside of the New Jerusalem where dogs and whore mongers which represented sinners. IF THE NEW JERUSALEM WAS HEAVEN THERE WOULD NOT BE SINNERS OUTSIDE THE PEARLY GATES. On the other hand, if the New Jerusalem represents Gods bride the church then yes, outside Gods church there would be dogs and whore mongers (sinners). (Revelation 22:15) Many were taught this is Heaven but verse 2 tells us it's the New Jerusalem. We know this is not Heaven because It comes out of Heaven, therefore it cannot be Heaven, It's Spiritual. Look at verse 25 Why would Heaven need gates? The gates are always open because new Christians are added daily. Also Sin continues outside the gates of the New Jerusalem. Outside the gates are where the Non Christians are. They have not accepted Christ yet. Now if this were Heaven, there would be no sinners outside the gates. (Revelation 22:15)

John 14:2-3 is not talking about heaven. Where it says "In my Father's house are many..." Let me ask you this where is the fathers house? Before we answer that question, Jesus was getting ready to use the Romans to destroy His Fathers House the Old Temple. He was doing this so that the Old Covenant law would stop being practiced and be fulfilled. He became our one time sacrifice for sins and put an end to animal sacrifices that took place in that temple. On the day of Pentecost Gods people became the new temple where the holy spirit would indwell and replace the old temple. In the new covenant God's presence would indwell the new temple, which is inside his believers. That's why were told "that where I am, you may be also." We indwell IN Him. The body of Christ is the father's house, the kingdom, church and New Jerusalem. Now that is a Mansion! Our Mansion is IN Christ that's why in Ephesians 2:5 it says even when we were dead in our transgressions, made us alive together with Christ (by grace you have been saved) When we are saved we are seated in heavenly places with Christ spiritually while we are on this earth. I believe it gives us the spiritual eyes not only to see Him but to see the heavenly things now on this earth. And when our physical bodies die our spirit/soul continues to live in Christ in heaven. Yes in heaven, we will be able to perceive spiritually things as physical. But if you're looking for some physical Kingdom you're missing the whole point of being a Christian, being IN HIM.

In Revelation 21:5 "To the thirsty I will give from the spring of the water of life without payment." The water of life is available to all who accept Jesus. Isaiah 55:1 promises that "Come, everyone who thirsts, come to the waters." This is the promise of a new, everlasting covenant per Isaiah 55:3. And In John 4:14 and 7:38 Jesus promised that whoever drinks of the living water he offers will have eternal life.