This passage is a Kodachrome shot of what we'll experience in heaven. The book of Revelation was written by the Apostle John as revealed to him by the Spirit of God. In chapter one, John meets Jesus again, long after the resurrection and ascension. We can logically divide the book in this way. Therefore our text is what John spiritually saw far in the future.
Doors are important in the imagery of the book.
If Laodicia represents the last days of the church age, then we have a sad picture of God's people today. John was about to see worship in eternity future. It occurs 46 times throughout the book. In chapter 4 alone it occurs 14 times. What a comforting thought to remember that in the midst of the chaos of the last days, God is still on His throne.