Will there be tears, death or pain in eternity?
No. Scripture teaches that in the eternal state God will wipe away every tear, and there will be no more death, sorrow, crying, or pain of any kind.
Once the new heaven and new earth are established, all the sorrow of this present life comes to an end. As it is written, "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" (Revelation 21:3-4). This shows that death, sorrow, crying, and pain belong only to the former things, the old order that passes away when God dwells fully with His people.
Eternal life itself means that death and sickness no longer have any power or dominion. Believers who hear the Lord's voice and follow Him receive eternal life and shall never perish, and no one is able to pluck them out of His hand. Those who hear His word and believe on Him who sent Him have already passed from death unto life and will not come into condemnation.
In that eternal state, there is also no more curse, for the throne of God and of the Lamb will be there, His servants will serve Him, and they will see His face. The pure in heart are promised that they will see God, and this face to face fellowship replaces the groaning and travail that once marked the old creation. What was sown in corruption, dishonour, and weakness is raised in incorruption, glory, and power, so the very bodies of the redeemed are made fit for a life with no more death, sorrow, crying, or pain.
The scriptures
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.
My sheep hear my voice, and I know them, and they follow me: And I give unto them eternal life; and they shall never perish, neither shall any man pluck them out of my hand.
Verily, verily, I say unto you, He that heareth my word, and believeth on him that sent me, hath everlasting life, and shall not come into condemnation; but is passed from death unto life.
And there shall be no more curse: but the throne of God and of the Lamb shall be in it; and his servants shall serve him: And they shall see his face; and his name shall be in their foreheads.
Blessed are the pure in heart: for they shall see God.
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.
From the books
This answer is drawn from these passages in the Mary Banks Faith Library.