The book of Revelation concerns Israel and non-believers, and not the Church. As A Premillennialist, I believe that the Church of Jesus Christ is Raptured in Rev. 4:1.
I should be noted, that The seven churches were composed of Jews who believed in Jesus Christ, and they received doctrine for the nation of Israel from an apostle to Israel about the kingdom prophesied in the Old Testament.
"Asia" was a Roman province, only about the size of Iowa, located in what is now the western part of Turkey. The book of Revelation contains doctrine for the kingdom dispensation and was written to the early Jews who believed in Christ rather than to the partly Jew but mostly Gentile churches to which Paul preached the revealed mysteries of this grace dispensation.
Where in Rev 4:1-2 does it say anything about a pretrib Rapture of the Church? All I read is that John was in the Spirit while on the Isle of Patmos being held there as a prisoner for teaching the word of God when he received these visions from the angel Jesus sent to him and not literally taken up to Heaven as that would come against what Jesus said in John 3:13.
Rev 1:1-11
God gave these revelations to Jesus first and then he passed it onto John through a ministering angel through visions as God reveals those things that have to come to pass before the return of Jesus. The revelations are for the Church in John’s time plus every generation from that time on until Jesus returns in the air to gather up his Bride to the clouds as they receive their new glorified bodies and meet Jesus in the air, 1Corinthians 15:5-58; 1Thessalonians 4:13-18.
The seven churches represent all who are in Christ and He in them from generation to generation. Only through that of Jesus being the final sacrifice for the atonement of sin can we become a royal priesthood joined to him, 1 Peter 2:9. Jesus comes in the clouds and every eye will see him, even those who have rejected him and many will loudly mourn his coming as they have never repented of their sin and now the door of salvation will be closed forever. God is never changing and his word will never come back void, Isaiah 55:11.
John was the last Apostle alive of the original twelve Disciples at the time of his writing these letters to the Church. John was with John the Baptist until that time he was called to be part of the twelve Disciples of Jesus. He was called the beloved of Jesus as he left John the Baptist to follow after Jesus. John was the only Disciple that witnessed the crucifixion of Christ as all the other Disciples fled when Jesus was arrested as they were in fear they would be arrested also, Matthew 25:56, but after Jesus ascended to heaven they were all made Apostles of Christ filled with the Holy Spirit that guided them.
John was the Apostle to the Church in Ephesus where he lived and wrote four epistles, John, First, Second and Third John. He was exiled to the isle of Patmos by the Roman Emperor Domitian for preaching the word of God in the Roman province of Asia where the seven Churches were located. It is said that John was in his nineties when he was exiled and probably released around 97 AD after Domitian died. John was born around 6 AD and died around 100 AD.
John was in the Spirit (being in the Spirit means being in the presence of Gods Spirit that makes the flesh to weak to stand, John 18:6) on the Lords day that was a chosen day of God in his timing and purpose to reveal these revelations to John. He was not literally taken up to heaven, John 3:13, but only in the Spirit.
John first heard a great voice as a trumpet as the voice was very distinct to him like that of hearing a trumpet sound in all its great power and authority. John heard the voice 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.(This was around 95AD after the Church was first established on the day of Pentecost)
Ephesus would be the nearest Church to this isle and as supply ships came in someone from the Church would come and take parts of these letters and hide them on their person and take them back to the Church of Ephesus as they were dispersed between all seven Churches.