John 3:28 You yourselves bear me witness, that I said, I am not the Christ, but that I am sent before him. He that has the bride is the bridegroom: but the friend of the bridegroom, which stand and hear him, rejoice greatly because of the bridegroom’s voice: this my joy therefore is fulfilled.
The friend of the bridegroom is the one who played an important part in the wedding ceremonies, and sometimes conducted the negotiations between the bride and groom. The friend, at the time of the first meeting of the bride and groom, stands just outside the door to hear how delighted the groom is about his bride.
‘This my joy, therefore, is fulfilled’ This does not mean John was not to be a member of the future bride of Christ, for he will be. The heavenly city, the New Jerusalem, is the bride of Christ (Rev. 21:2, 9-10). All Old Testament saints (Heb. 11:10-16) and all New Testament saints will go there (Heb. 13:14; John 14:1-3). This includes John the Baptist and other saints of all ages from Abel to the end of the first resurrection (1Cor. 15:23, 51-58; 1Thess. 4:16; Rev. 20:4-6). All John expresses here is the fact that he is not the bridegroom, but his friend, as are all saints who are friends of the bridegroom (John 15:13-15). As John invited people to Christ, so do all the members of the bride (Rev. 22:17).