The book begins with the phrase, "the revelation of Jesus Christ." Verse 1 goes on to report that the revelation is signified, and in verse 2 it becomes the testimony of Jesus, something that John can see. So John speaks of two things: the "word of God" and the "testimony of Jesus." The word of God is likely a reference to what was John's Scriptures, the collection of writings that we know today of as the Old Testament.
The book of Revelation alludes to the Old Testament hundreds of times, employing a word here, a phrase there, a name somewhere else. It recalls the places of the Old Testament--Babylon, Egypt, and Jerusalem--as well as the people of the Old Testament: David, Jezebel, and Balaam. The Old Testament is like a current flowing under the surface of the book, yet affecting everything it touches.
A few year ago I visited Russia with my oldest daughter to teach a couple classes. At the time it wasn't certain if Communism was gone or would make a comeback. So one of the "must sees" on my to-do-list was Red Square, Lenin's tomb, and the Kremlin in the capital city of Moscow. Tammy, on the other hand, was more interested in shopping for a nesting doll. So after we did the tourist stuff we headed for Moscow's market, where you could bargain for local handicrafts.
Nesting dolls are a Russian specialty. Usually made of wood, they are a series of hollow dolls beautifully decorated on the outside and that can be opened to reveal successively smaller versions of the outer doll. After some searching we found a black doll in seven layers with a beautiful multicolored scene on each one, all emphasizing the color red. Tammy was pleased with the doll and negotiated with enthusiasm, bring the price down to $7 ( good deal at the time).
In its use of the Old Testament the book of Revelation is like a nesting doll. You could read the book without reference to the Old Testament and think you have grasped the whole picture. But when you discover the text beneath the surface it begins revealing the deeper truths placed in the book. The book of Revelation is like the finale of the biblical symphony, drawing all of the Bible's themes together in a thrilling conclusion.
Lord, thank You for the deep things of Your Word. It keeps me coming back to the Bible again and again, helping me grow spiritually as I continue to study. May I never be satisfied with a surface understanding.