There appears to be about six passages that clearly deal with the “bride” in the New Testament.

1. The first is in John 3:29. In this passage, John the Baptist calls himself the friend of the bridegroom. It appears, therefore, that John the Baptist and other Jewish saints prior to the establishment of the church, were apparently not a part of the bride (Old Testament saints would be invited guests to the wedding). On several occasions Christ calls Himself the bridegroom.

2. Ephesians 5:25-32 says the husband and wife picture Christ and the church. This language obviously implies a bride and in so doing tells us that the church is the bride. (cf. 2 Cor 11:2; Rom 7:4; Col 1:28)

3. Rev 18:23 the bride has a voice that is distinct from that of the bridegroom and will one day be unable to be heard in “Babylon.”

4. Rev 19:6-9 describes the “marriage of the Lamb,” which refers to a bride, the Lamb’s wife (v.7). The passage doesn’t specifically say who the bride is but mentions that she is adorned in fine linen, which “is the righteousness of the saints.” Additionally, there are ‘invitees’ to the wedding…people who are saved but obviously not the ‘bride’ (the bride isn’t invited to her own wedding…). 

5. In Rev 21:2 a city is adorned “as” a bride. In v.9 an angel comes and specifically says that he is about to show us the bride. In v.10 we are taken to a high mountain from which we are shown a great city descending out of Heaven from God. This city is identified as holy Jerusalem (not the bride). From verse 11 to the end of the chapter we are told the following

…the city has the glory of God

…the light of the city was beautiful like a clear, precious jasper stone

    …a wall surrounded the city with 12 gates named for the 12 tribes of Israel

…the gates were spread evenly, 3 to each side of a four-square city, each was a giant pearl

…The wall was built on 12 foundations (the 12 Apostles), garnished with precious stones

…the city was 12,000 furlongs = 1500 miles square and tall (either cube or pyramid shape)

    …the wall looked like Jasper, the city like pure, clear gold

    …there was a single street in the city like transparent glass

    …there was no temple (the Lord God Himself was the temple of the city)

    …there was no need for light as the glory of God and the Lamb was the light of it

    …people from every nation have been saved and are living within its walls

    …the gates of the city are never shut – there is no night

    …only saved souls will ever be allowed inside

It is necessary to point out that we are never told the city is the bride, just that it is adorned as a bride – and then the adornment is described. This passage is by far less clear, in my opinion, than the passage in Ephesians. Also, Heavenly Jerusalem is called the home of the church (and thus bride) in Heb 12:22-24.

6. The final passage is Revelation 22:17, where the bride invites sinners to God’s free salvation in Jesus Christ. 

Taking all of these passages together, I believe the bride of Christ consists of all born again believers in this church age.

A passage that relates the church to a building (and thus city?) would be Eph 2:18-22

For those who claim that we can’t do anything to get ourselves ready or “cleaned up”, I would heartily disagree (cf. 1 John 3:2-3; 2 Cor 7:1; Heb 12:14; 2 Peter 1:4; 3:14; and many others!). We can’t save ourselves by good works, but, with the power of the Holy Spirit, we are supposed to be conforming ourselves to His image more every day (sanctification).