The angels words reinforce an important truth: Everything John has seen in Revelation will come to pass. What the inspired apostle has written is not mystical; the Apocalypse is not a record of his bizarre dreams or the result of an overactive imagination. It is not an allegory from which readers can extract hidden meanings of their own concoction. It is an accurate description of events and persons yet to come.1the Lord God of the holy prophets
The MT text has τῶν πνευμάτων τῶν προφητῶν [tōn pneumatōn tōn prophētōn] : of the spirits of the prophets. Regarding the testimony born by the spirits of the prophets, see commentary on Revelation 19:10.
to show His servants the things which must shortly take place
The same Greek phrase occurs in the introductory verse of this book. The expectation of His imminent coming is found throughout the book. See commentary on Revelation 1:1.
The exactness, detail, and precision with which earlier prophecies already fulfilled came to pass forms the pattern for those yet to be fulfilled. Gods prophetic record is perfect. He predicted Israel would go into captivity, and the nation did (Lev. Lev. 26:33-39). He predicted the destruction of Babylon (Isa. Isa. 13:1-Isa. 14:27; Jer. Jer. 50:1-Jer. 51:1) and Tyre (Isa. Isa. 23:1 ff.), and those cities were destroyed. He predicted that Messiah would be born in Bethlehem (Mic. Mic. 5:2), to a virgin (Isa. Isa. 7:14), and be killed by sinners (Isa. Isa. 53:7-10) and He was. Thus, when God predicts future events, such as the rapture of the church, the rise of Antichrist, the seal, trumpet, and bowl judgments, the Battle of Armageddon, the return of Jesus Christ, and His thousand-year earthly kingdom, those events will just as certainly come to pass [Isa. Isa. 46:9-11].2
1 John MacArthur, Revelation 12-22 : The MacArthur New Testament Commentary (Chicago, IL: Moody Press, 2000), Rev. 22:6.