The Churches of Revelation 2 and 3 are the Seven outward and/or institutional manifestations of Christianity during the Church Age.
“11 Saying, I am Alpha and Omega, the first and the last: and, What thou seest, write in a book, and send it unto the seven churches which are in Asia; unto Ephesus, and unto Smyrna, and unto Pergamos, and unto Thyatira, and unto Sardis, and unto Philadelphia, and unto Laodicea. 12 And I turned to see the voice that spake with me. And being turned, I saw seven golden candlesticks; 13 And in the midst of the seven candlesticks one like unto the Son of man, clothed with a garment down to the foot, and girt about the paps with a golden girdle.” Revelation 1:11-13
“20 The mystery of the seven stars which thou sawest in my right hand, and the seven golden candlesticks. The seven stars are the angels of the seven churches: and the seven candlesticks which thou sawest are the seven churches.” Revelation 1:20
There are also 24 elders on 24 thrones:
“4 And round about the throne were four and twenty seats: and upon the seats I saw four and twenty elders sitting, clothed in white raiment; and they had on their heads crowns of gold.” Revelation 4:4
These elders confess that they are Christians who were redeemed by Jesus Christ:
“8 And when he had taken the book, the four beasts and four and twenty elders fell down before the Lamb, having every one of them harps, and golden vials full of odours, which are the prayers of saints. 9 And they sung a new song, saying, Thou art worthy to take the book, and to open the seals thereof: for thou wast slain, and hast redeemed us to God by thy blood out of every kindred, and tongue, and people, and nation; 10 And hast made us unto our God kings and priests: and we shall reign on the earth.” Revelation 5:8-10
The graphic shows 7 tables arranged facing each other behind which are 24 thrones.
This isn’t to commend outward Christianity – much of it is incredibly apostate, idol worshipping, fornicating, Bible-rejecting, rebellious, and unsaved – they have all the faults described by Christ against them in Revelation chapters 2 and 3.
But nevertheless it is what it is – the outward form in which Christianity as a 7 pronged institution has manifested itself over 2,000 years. What we currently see in a raw unfinished form presently is to be the eventual framework for the eternal Church of Christ in glory, his administration of the Kingdom of Heaven in the world to come. The schematic above is a theory projecting what that might look like.