John does not represent the church in Rev 4:1 and there is no scripture to prove that he was a representative of the church. The idea that Rev 4:1 represents the resurrection of the church before the very events that John had visions about is a made up, non biblical doctrinal belief created by those who would perpetuate the Pre Tribulation resurrection doctrinal belief. Proof that it is a false belief is that there are no scriptures to re enforce that belief. The Apostle John lived for many years after he finished the book of Revelations.
Rev 4:1 After this I looked, and, behold, a door was opened in heaven: and the first voice which I heard was as it were of a trumpet talking with me; which said, Come up hither, and I will shew thee things which must be hereafter.
Yes but the physical body of John did not go up into heaven. He was translated up to heaven in the spirit and he didn't stay in heaven, he was sent back. Otherwise he would never have been able to write down on parchment his visions. John was imprisoned on the island of Potmos when he had his visions and wrote the book of Revelation.
Rev 1:9 I John, who also am your brother, and companion in tribulation, and in the kingdom and patience of Jesus Christ, was in the isle that is called Patmos, for the word of God, and for the testimony of Jesus Christ.
Some believe he died of natural causes. However no one knoews if he died on Potmos or was released from prison and died some place else.
Rev 4:2 And immediately I was in the spirit: and, behold, a throne was set in heaven, and one sat on the throne.
No flesh and blood can not go into heaven.
1Co 15:50 Now this I say, brethren, that flesh and blood cannot inherit the kingdom of God; neither doth corruption inherit incorruption.