Q. Rev. 19:8 says: “It was given to her to clothe herself in fine linen, bright and clean; for the fine linen is the righteous acts of the saints”. The verse tells us that she clothed herself with the righteous acts of the saints. The verse does not say that she was clothed with the blood of the Lamb. There is a difference. And Revelation 21:2says, “And I saw the holy city, new Jerusalem, coming down out of heaven from God, made ready as a bride adorned for her husband. So Who is the bride of Christ?
A. In the original language, Rev. 19:8 says the fine linen is the righteousness of the saints, not their righteous acts. The translators of the version you’re quoting from added the word acts. (Read Rev. 19:8 in the KJV to confirm this.) Our righteousness is imputed to us by faith in the shed blood of the Lamb (Romans 3:21-22).
In Rev. 21:2 the New Jerusalem is adorned “as” a bride. This means no effort has been spared to make the New Jerusalem as beautiful as possible, just as no effort is spared to make a bride her most beautiful self on her wedding day. The New Jerusalem is not the bride, but is the place where the Bride will live. The Church is the Bride of Christ (2 Cor. 11:2, Ephes. 5:25-27).