“I saw a new heaven and a new earth; for the former heaven and the former earth had passed away, and the sea is no more. I saw also the holy city, New Jerusalem, coming down out of heaven from God and prepared as a bride adorned for her husband. With that I heard a loud voice from the throne say: ‘Look! The tent of God is with mankind, and he will reside with them, and they will be his peoples. And God himself will be with them. And he will wipe out every tear from their eyes, and death will be no more, neither will mourning nor outcry nor pain be anymore. The former things have passed away.’ And the One seated on the throne said: ‘Look! I am making all things new.’ Also, he says: ‘Write, because these words are faithful and true.’”​—Revelation 21:1-5.

Not mortal humans but God himself gives a guarantee regarding these blessings. He is the One who says Re 21:5: “Look! I am making all things new.” Yes, and Jehovah God told the apostle John: “Write, because these words are faithful and true.”