19 Write what you've seen, the things that are and the things that will be later.
20 The seven stars and seven candlesticks are the seven churches.
A few more words about this episode
Things that will soon happen (1:1)
Anyone who thinks that the Book of Revelation (or the Apocalypse of John) is a prophecy about things that are going to happen in the 21st century, hasn't read the first verse of the book (or any of these verses: Rev 1:3; 3:11, 22:6, 22:7, 12, 20)
I'm John, writing to you from the island of Patmos. (1:9)
Christians have traditionally identified John of Patmos as John the Apostle, whom they also thought was the author of the Gospel of John and the letters of John. However, the author of those writings didn't claim to be the apostle John, and modern scholars agree that he wrote none of them. Nothing much is known about the actual author of Revelation beyond what this verse says: it was written by a man named John who lived on the eastern Mediterranean island of Patmos.
I was in the spirit on the Lord's day (1:10)
This is the only occurrence of "the Lord's day" in the Bible. It probably refers to Sunday, which by this time (70-100 BCE) had begun to replace the Sabbath as the main weekly day of worship.
From John, Jesus, and the seven spirits to the seven churches in Asia (1:4)
Seven is John's favorite number. The number is mentioned 48 times in the book of Revelation - including seven churches, spirits of God, candlesticks, stars, lamps, seals, horns, eyes, angels, trumpets, thunders, heads, crowns, plagues, vials, mountains, and kings.
