When Christ will come in glory at the end of the ages, and God will be all in all, then will come the new heaven and new earth foretold by the prophet Isaiah and described in the book of Revelation. (cf. Isaiah 65:17-66:24)
Then I saw a new heaven and a new earth; for the first heaven and the first earth had passed away, and the sea was no more. And I saw the holy city, new Jerusalem, coming down out of heaven from God, prepared as a bride adorned for her husband; and I heard a great voice from the throne saying, “Behold, the dwelling of God is with men. He will dwell with them, and they shall be His people, and God Himself will be with them; He will wipe away every tear from their eyes, and death shall be no more, neither shall there be mourning nor crying nor pain any more, for the former things have passed away.”
And He who sat upon the throne said, “Behold, I make all things new.” Also He said, “Write this, for these words are trustworthy and true.” And He said to me, “It is done! I am the Alpha and the Omega, the beginning and the end. To the thirsty I will give water without price from the fountain of the water of life. He who conquers shall have this heritage, and I will be his God and he shall be my son. But as for the cowardly, the faithless, the polluted, as for murderers, fornicators, sorcerers, idolaters, and all liars, their lot shall be in the lake that burns with fire and brimstone, which is the second death.” (Revelation 21:1-8)
Behold I am coming soon, bringing my recompense to repay everyone for what he has done. (Revelation 22:12)
To gain the “heritage” of the New Jerusalem is the whole meaning of life, the sole purpose of man’s being created by God. “He who conquers shall have this heritage.” And as St. Paul has said simply, “We are more than conquerors through Him who loved us.” (Romans 8:37)
For I am sure that neither death, nor life, nor angels, nor principalities, nor things present, nor things to come, nor powers, nor height, nor depth, nor anything else in all creation, will be able to separate us from the love of God in Christ Jesus our Lord. (Romans 8:38-39)
For this reason I bow my knees before the Father’ from whom every family in heaven and on earth is named, that according to the riches of His glory He may grant you to be strengthened with might through His Spirit in the inner man, and that Christ may dwell in your hearts through faith; that you, being rooted and grounded in love, may have power to comprehend with all the saints what is the breadth and length and height and depth, and to know the love of Christ which surpasses knowledge, that you may be filled with all the fullness of God. (Ephesians 3:14-19)
To be “filled with all the fullness of God” – this, and this alone, is what Orthodox spirituality is about.