A Jehovah Witness and I spoke the other day and he explained to me that JWs believe that we'll live on earth after we die.
What scripture, if any, do they use to back this belief?
The idea comes from Revelations 21
1 Then I saw “a new heaven and a new earth,” for the first heaven and the first earth had passed away, and there was no longer any sea.
The problem with interpreting Revelations is that there's a lot of debate on what it actually means.
Will we live on a new earth? Yes in the sense that God will give us a place to live.
Will it be identical to the old earth (with tornadoes, volcanoes, etc)? Who knows!
The New World Translation of this doesn't really vary. You can read that if you'd like.
Jehovah's Witnesses, as myself, believe in an earthly paradise. This paradise will be the restoration of what Adam and Eve lost when they sinned. We view Psalms 37:11, 29 as a prophecy of this restoration. Jesus will rule from heaven the humankind with 144000 corulers, including resurrected, for 1000 years. We believe that some prophecies for this time are the following:
Isaiah 45:18 (all quotations from the NIV)
For this is what the LORD says— he who created the heavens, he is God; he who fashioned and made the earth, he founded it; he did not create it to be empty, but formed it to be inhabited— he says: “I am the LORD, and there is no other.
May grain abound throughout the land; on the tops of the hills may it sway. May the crops flourish like Lebanon and thrive like the grass of the field.
No one living in Zion will say, “I am ill”; and the sins of those who dwell there will be forgiven.
He will wipe every tear from their eyes. There will be no more death’ or mourning or crying or pain, for the old order of things has passed away.
17 “See, I will create new heavens and a new earth. The former things will not be remembered, nor will they come to mind. 18 But be glad and rejoice forever in what I will create, for I will create Jerusalem to be a delight and its people a joy. 19 I will rejoice over Jerusalem and take delight in my people; the sound of weeping and of crying will be heard in it no more. 20 “Never again will there be in it an infant who lives but a few days, or an old man who does not live out his years; the one who dies at a hundred will be thought a mere child; the one who fails to reach[a] a hundred will be considered accursed. 21 They will build houses and dwell in them; they will plant vineyards and eat their fruit. 22 No longer will they build houses and others live in them, or plant and others eat. For as the days of a tree, so will be the days of my people; my chosen ones will long enjoy the work of their hands. 23 They will not labor in vain, nor will they bear children doomed to misfortune; for they will be a people blessed by the LORD, they and their descendants with them. 24 Before they call I will answer; while they are still speaking I will hear.
Jehovah's witnesses will also use other bible texts to back up the idea of a 'paradise earth', although the exact combination of these two words do not appear in the bible and sometimes discussion can arise about the 'correct' interpretation of the word 'land/earth'.
The most important ones (or the first that come to my mind) are:
'Happy are the mildtempered ones since they will inherit the earth'
'Let your will take place as in heaven, also upon earth.'
'But there are new heavens and a new earth that we are awaiting according to his promise, and in these righteousness is to dwell.'
This idea of a new heaven and earth is also already known in the OT, e.g. Isaiah 66:22.
OT texts that stress a 'promised land' or the idea that the earth or righteous ones who inhabit it, will remain for ever, are also used to support the idea of a paradise earth: e.g. Deuteronomy 30:20; Psalm 37:29, Proverbs 2:21-22 (or a contrario Proverbs 10:30) and Ecclesiastes 1:4.
JW's further point to certain OT texts that heavily stress that humans have an earthly destination or that the earth is destined to be inhabited, e.g.:
Psalms 115:16 (NWT): 'As regards the heavens, to Jehovah the heavens belong, but the earth he has given to the sons of men.'
Isaiah 45:18 (NWT): '...God, the Former of the earth and the Maker of it, who did not simply create it for nothing, who formed it even to be inhabited.' See also Genesis 1:28 (NWT): 'fill the earth and subdue it'.
Note: the difference in rewards for the faithful ones (eternal life in heaven or eternal life on a paradise earth) is based on a special interpretation of John 10:16 (the 'other sheep' are not interpreted as non-Jews, but as persons who look forward to live for ever on paradise earth and not in heaven).