“After these things I saw, and, look! an opened door in heaven, and the first voice that I heard was as of a trumpet, speaking with me, saying: ‘Come on up here, and I shall show you the things that must take place.’” (Revelation 4:1) John in vision penetrates the invisible heavens of Jehovah’s presence, exalted far above physical outer space as explored by human astronauts, even far above the galaxies of the material universe. As though by entering an opened door, John is invited to feast his eyes on a breathtaking panorama of the ultimate spirit heavens where Jehovah himself is enthroned. (Psalm 11:4; Isaiah 66:1)

Undoubtedly, Jehovah is the majestic Source of the summons. (Revelation 1:1) He has opened the door so that John, in vision, can enter the most holy location in all the vast realm of Jehovah’s sovereignty.