Symbolism in Revelation

"The symbolism in Revelation and other NT prophetic-apocalyptic passages falls into three categories. First, some symbolism is explained in the book, e.g., the seven stars=the seven churches, Rev 1:20; the great dragon=the Devil, Satan (12:9). Second, some symbolism unexplained in the NT text is paralleled by Old Testament imagery, e.g., the tree of life, 2:7; 22:2/Gen 2:9; the four horsemen, Rev 6:1–8/Zech 6:1–8. Third, some unexplained NT symbols find parallels in extra-biblical sources, whether Jewish or pagan, e.g., the great white throne of Rev 20:11/1 En. 18:8; the seals on the book, Rev 6 part of the Roman practice of sealing a will was that the seal be broken only by a rightful heir."

William J. Larkin, Greek is Great Gain: A Method for Exegesis and Exposition (Eugene, OR: Wipf & Stock, 2008), 133.