Rev. 21:2: "And I John saw the holy city, new Jerusalem, coming down from God out of heaven, prepared as a bride adorned for her husband."
This next verse also answers your previous question about Jeremiah: "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." v.3.
Rev. 21:9 "And there came unto me one of the seven angels which had the seven vials full of the seven last plagues, and talked with me, saying, COME HITHER, I WILL SHEW THEE THE BRIDE, THE LAMB'S WIFE. And he carried me away in the spirit to a great and high mountain, and shewed me that GREAT CITY, THE HOLY JERUSALEM, descending out of heaven from God." v.9,10.
According to the Book of Revelation, Jerusalem is the Bride, the Lamb's wife. The NEW JERUSALEM that descends out of heaven from God.
The word Bride is used only 5 times in connection with believers (Jn. 3:29, Rev. 21:2,9:22:17). The word bridegroom is used 10 times in connection with believers (Mt. 9:15;Mk.2:19-20; Lk.5:34-35; Jn. 3:29).-Dake's Annotated Reference Bible, b 28-4; c303-4. (Notice none of these Scriptures appear in any of Paul's epistles, they are all from the Kingdom gospel, prophecy). All these passages refer to believers who will live in the New Jerusalem, which is the bride, the Lamb's wife. (21:2, 9-10).
Which leaves this age, the Mystery. We, as believers, will also live in the New Jerusalem, the Lamb's wife. But notice in all of Paul's writings we are NEVER referred to as a bride. We are referred to as the ONE NEW MAN.
"For he is our peace, who hath made both one, and hath broken down the middle wall of partition between us; having abolished in his flesh the enmity, even the law of commandments contained in ordinances; for to make in himself of twain ONE NEW MAN, so making peace: Eph. 2:15.
This also explains 2 Thess. Chapter 2. and who the "he" is that holds back the Wicked one, until "he" be TAKEN OUT OF THE WAY. (rapture). The Church the Body of Christ, the ONE NEW MAN.
As to what we will be doing during the tribulation and millennium, we know TWO things we'll be doing for sure: "Do ye not know that the saints shall judge the world?..." and "Know ye not that we shall judge angels?..." 1 Cor. 6:2,3.