The New Heaven and the New Earth:  21:1-4. 
The final two chapters of Revelation describe the vision of new heaven and new earth.  Using the imagery of marriage,  John shows the eternal union of believers with Christ here.  This is the bright and glorious future awaiting  for God's people.  When Christ’s thousand year reign ends, the millennium merges into eternity. John saw a new heaven and a new earth.  For the first heaven and the first earth are passed away; and there is no more sea (Revelation 21:1). It is not going to be a cleaned-up or a renovated heaven and earth. They are new because God made them new.  He makes all things new (Revelation 21:5).  It is true in our salvation also.  If anyone is in Christ he is a new creation (2 Corinthians 5:17). Reformation and good work will not save us. Scripture clearly teaches that we should look forward to new heaven and new earth (2 Peter 3:10-13). And John saw the holy city, the New Jerusalem coming down from God out of heaven like a bride, beautifully dressed for her husband (Revelation 21:2). Here we see the picture of the church, the bride of Christ (Revelation 21:9). This speaks of the believer's eternal relationship with God in the New Jerusalem. Heaven is their eternal home where God is worshiped and Christ is praised for His worthiness.  It is  also God's eternal and perfect dwelling place where believers dwell with Him in the perfect union.  Many people deny the reality of heaven and eternal judgment. Some hold the distorted view that heaven will be a dull place of church service.  But heaven is the most satisfying place of splendor and fellowship with God and believers. 
 
Behold God is with Men: 21:5-8.
Then John heard a loud voice from heaven saying “Behold the tabernacle of God is with men”.  God always desired to dwell with men. He created us to fellowship with Him (Gen 3).  God wanted to dwell in the midst of Israel in the tabernacle (Exodus 25:8).   Christ first came to dwell among us in order to save us (John 1:14).  He dwells in the midst of believers in the church today (1 Timothy 3:15). The Holy Spirit dwells in us to comfort and guide us (John 14:16-18). God will wipe away tears from our eyes.  There will be no more death or sorrow or crying or pain.  The former things on earth have passed away and behold God makes all things new (21:4, 5). It is the poetic way of saying there will be no curse of sin in New Jerusalem. There will not be any sin because Satan has been thrown into the lake of fire (20:7-10).  New Jerusalem will be a far better place than Millennium because only believers will be there.  Those who have conquered will be rewarded for their faithful serve (21:7).  Heaven is our Father's house (John 14:2).  One day all of Sin's influence will be gone and believers will be with Christ forever.  
 
The New Jerusalem: 21:9-22. 
John was given the vision of the New Jerusalem, the bride of the Lamb descending out of heaven from God (Revelation 21:9). John describes the glories of heaven here. Its location is not specifically told. But it will be in the vicinity of the earth. It is a literal city. Heaven comes to earth where God will dwell with His people forever in the holy city. This new heaven and earth will be new in quality (Romans  8:19-24).  There is no corruption, decay, death and sin in heaven. From Genesis to Revelation God promises to dwell in the midst of His people (21:8). Very few people received a glimpse of heaven's glory (2 Corinthians 12:2-5).  Its radiant glory is like sparkling costly jewels. It is beyond human comprehension. Here the redeemed believers would live forever, untouched by the power of sin.  They are cleansed by the blood of the Lamb and without any blemish (Ephesians 5:27). The glory of God permeates this city. It has a great and high wall with twelve gates. This wall is made of jasper and pure gold clear as glass (Revelation 21:18). On the gates, names of the twelve tribes of Israel are written. Each of the gates is made of one giant pearl (Revelation 21:21). The wall of New Jerusalem has twelve foundations. The names of the twelve apostles are written on them.  It may represent the twelve apostles who laid the foundation of the church (Ephesians 2:20). New Jerusalem covers an area of 1500 miles in length, breadth and height (Revelation 21:16).  Scholars suggest that Its shape may be like a cube.  In the tabernacle, the Most Holy Place was a cube.  It was the perfect place where God was dwelling. The precious stones and pure gold used here speak of the unimaginable beauty and glory of New Jerusalem. There is much we do not know about New Jerusalem. Undoubtedly it will be a place of wonder where we worship and fellowship with God.

The glory of the New Jerusalem:  21:22-27. 
John saw no temple in the holy city, for its temple is the Lord God the Almighty and the Lamb (Revelation 21:22). There is no more need for a temple because we meet God Himself directly in the person of Christ. There will be complete access to God to fellowship with Him. Human hearts long for God and we are created to appreciate His glory.  Heaven will be the perfect place of God's greatness and splendor. There is no need for the sun or moon because the glory of God illuminates the city and the Lamb is its light. The gentile nation will enjoy the beauty and glory of New Jerusalem and their kings will bring tributes to the Lamb. Its gates never will be shut because nothing unclean or sinful will ever enter the holy city. This is the blessed hope of the redeemed people of God.  This thought motivated the Old Testament saints to endure hardship and long for heaven (Hebrews 11:16). This is the kingdom that cannot be shaken. (Hebrews 12:28). Those who endure hardship for Christ and remain faithful will have a rich entrance into the eternal kingdom of Christ (2 Peter 1:11).  Are you ready for that by receiving Jesus Christ as your Lord and Savior?