Consider John’s description of the fabulous city of the redeemed, the New Jerusalem, in Revelation 21:2, Revelation 21:9-27. What do these verses imply about the unity and harmony that will exist in this city?
Read Revelation 22:1-5. The river of life that flows from the throne of God with the tree of life that spans it are two other important features of the new city. What will be their purpose on the new earth?
The tree of life, which Adam lost access to through his transgression (Gen. 3:22-24), will be restored by Christ in the New Jerusalem. Access to this tree is one of the promises to those who overcome (Rev. 2:7). Its bearing twelve kinds of fruit, a new kind each month, may suggest a reason that in the new earth “from one New Moon to another, and from one Sabbath to another, all flesh shall come to worship before Me, says the LORD” (Isa. 66:23, NKJV). The reference to the “healing of the nations” also underscores God’s intent to remove all barriers between people and to restore humanity to its original purpose: to restore all people, tribes, and nations into one undivided family, living in harmony and peace, united to give glory to God.
“The healing of the nations’ refers figuratively to the removal of all national and linguistic barriers and separation. … The leaves of the tree of life heal the breaches between nations. The nations are no longer ‘gentiles’ but are united into one family as the true people of God ([compare] Rev. 21:24-26). What Micah anticipated centuries earlier is now being fulfilled: ‘Nation will not lift up sword against nation, and never again will they train for war. Each of them will sit under his vine and under his fig tree, with no one to make them afraid’ (Mic. 4:3-4; [compare] Isa. 2:4). There on the banks of the river of life the redeemed will ‘invite his neighbor to sit’ (Zech. 3:10) with him under the tree of life. The curing quality of the leaves of the tree will heal all wounds – racial, ethnic, tribal, or linguistic – that have torn and divided humanity for ages.” – Ranko Stefanovic, Revelation of Jesus Christ: Commentary on the Book of Revelation, p. 593.