What will the saints do for eternity?
The saints will live forever in glorified spiritual bodies, reign and rule with Christ over the nations, judge the world and angels, and enjoy unbroken fellowship with God, seeing His face and receiving rewards for their faithfulness.
Scripture teaches that at the rapture the saints receive new, spiritual bodies in place of their natural ones. Paul explains that what is sown in corruption is raised in incorruption, sown in weakness and raised in power, sown a natural body and raised a spiritual body. This means death and sickness will no longer have any power over the saints, for they are given eternal life that can never be taken from them.
Eternity for the saints also means unbroken, face to face fellowship with God. They shall see His face, and His name will be in their foreheads. The partial knowledge they now have will give way to full knowledge, for what is in part will be done away, and they shall know even as they are known. God Himself will dwell with them, wipe away every tear, and there will be no more death, sorrow, crying, or pain, for the former things will have passed away.
The saints will also rule and reign with Christ for a thousand years, sitting on thrones and judging. Those who overcome are given power over the nations to rule them, and the saints will even judge the world and judge angels. This reign is given according to faithfulness, as pictured in the parable of the servants who were given authority over cities according to how well they had used what was entrusted to them; some are given rule over more, some over less, but all who overcome share in this rulership over the nations who remain on the earth like Adam.
Along with this reign come specific rewards: a crown of life for enduring trial, a crown of glory that never fades, a crown of righteousness for those who love His appearing, a new name written on a white stone known only to the one who receives it, and being made a pillar in the temple of God who shall go no more out. Overcomers are also promised to sit with Christ on His throne, to be given the morning star, and to receive everlasting joy, peace, and an eternal weight of glory that far outweighs any light affliction endured in this present life.
The scriptures
All flesh is not the same flesh: but there is one kind of flesh of men, another flesh of beasts, another of fishes, and another of birds. There are also celestial bodies, and bodies terrestrial: but the glory of the celestial is one, and the glory of the terrestrial is another. There is one glory of the sun, and another glory of the moon, and another glory of the stars: for one star differeth from another star in glory. So also is the resurrection of the dead. It is sown in corruption; it is raised in incorruption: It is sown in dishonour; it is raised in glory: it is sown in weakness; it is raised in power: It is sown a natural body; it is raised a spiritual body. There is a natural body, and there is a spiritual body.
And I heard a great voice out of heaven saying, Behold, the tabernacle of God is with men, and he will dwell with them, and they shall be his people, and God himself shall be with them, and be their God. And God shall wipe away all tears from their eyes; and there shall be no more death, neither sorrow, nor crying, neither shall there be any more pain: for the former things are passed away.
For we know in part, and we prophesy in part. But when that which is perfect is come, then that which is in part shall be done away. When I was a child, I spake as a child, I understood as a child, I thought as a child: but when I became a man, I put away childish things. For now we see through a glass, darkly; but then face to face: now I know in part; but then shall I know even as also I am known.
And I saw thrones, and they sat upon them, and judgment was given unto them: and I saw the souls of them that were beheaded for the witness of Jesus, and for the word of God, and which had not worshipped the beast, neither his image, neither had received his mark upon their foreheads, or in their hands; and they lived and reigned with Christ a thousand years.
Blessed and holy is he that hath part in the first resurrection: on such the second death hath no power, but they shall be priests of God and of Christ, and shall reign with him a thousand years.
He said therefore, A certain nobleman went into a far country to receive for himself a kingdom, and to return. And he called his ten servants, and delivered them ten pounds, and said unto them, Occupy till I come. But his citizens hated him, and sent a message after him, saying, We will not have this man to reign over us. And it came to pass, that when he was returned, having received the kingdom, then he commanded these servants to be called unto him, to whom he had given the money, that he might know how much every man had gained by trading. Then came the first, saying, Lord, thy pound hath gained ten pounds. And he said unto him, Well, thou good servant: because thou hast been faithful in a very little, have thou authority over ten cities. And the second came, saying, Lord, thy pound hath gained five pounds. And he said likewise to him, Be thou also over five cities.
And he that overcometh, and keepeth my works unto the end, to him will I give power over the nations: And he shall rule them with a rod of iron; as the vessels of a potter shall they be broken to shivers: even as I received of my Father. And I will give him the morning star.
Do ye not know that the saints shall judge the world? and if the world shall be judged by you, are ye unworthy to judge the smallest matters? Know ye not that we shall judge angels? how much more things that pertain to this life?
From the books
This answer is drawn from these passages in the Mary Banks Faith Library.