The Revelation of Jesus Christ, which God gave Him to show to His bond-servants, the things which must shortly take place; and He sent and communicated it by His angel to His bond-servant John... (Revelation 1:1 NASB)
The word Revelation comes from the Greek word, "apokalupsis", which means disclosure or revelation. We get our word apocalypse from it. There was a genre of apocalyptic literature at the time of Revelation, but the book of Revelation does not quite fit in the genre. While it does have remarkable symbols of history, it does not fit the genre in other ways. For instance, John, the author of Revelation, does not use a pseudonym. He uses his real name. Neither is Revelation history rewritten as prophecy. So the word "revelation" itself does not appear to be a term to indicate its following the tradition of other apocalyptic works.
Revelation makes allusions to many other biblical passages, particularly Old Testament passages. Over and over allusions are made to Daniel. In Revelation 1,there are allusions to Daniel chapter 2, chapter 7, 10, and other chapters. This can give us a clue to the framework in understanding Revelation.
The first verse of Revelation introducing the book follows a pattern found in Daniel, chapter 2 where Daniel is introducing an interpretation of a dream of King Nebuchadnezzar. King Nebuchadnezzar had a dream that troubled him. He demanded his wise men to tell him his dream and give the interpretation of the dream. God revealed to Daniel the dream and the interpretation. Nebuchadnezzar's dream was a symbolic dream of the future. Daniel tells King Nebuchadnezzar that God "has made known" the dream and that it "will take place in the latter days." Revelation has the corresponding elements in the opening, saying the God is going "to show" his bond-servants and that it "must take place shortly."
The word "show" in Revelation 1:1 comes from the Greek word, "semaino," which means to signify -- with the implication that communication will be shown in symbolic signs. The vision in Daniel 2 is highly symbolic; it pictures a statue that represents the Babylonian empire and future empires. We can expect that Revelation will be symbolic in its imagery.
What Daniel says will take place in the latter days, Revelation says must take place shortly. The Greek that is translated indicates that time that "is shortly taking place" also has the meaning the time has begun; that this is the beginning of time while will continue into its fullness to its consummation. The distant time of Daniel's era is referring to John's era. This age began with Jesus' advent, especially his death, resurrection, and ascension. We will see the pattern of the "already-and-not-yet" end-times of the period we live in. We are already in the era of "peace and grace" (v. 4 and 5) accomplished through the death and resurrection of Christ. Jesus is already the ruler of the kings of the earth (v. 5). All believers make up a kingdom of priests (v. 6), implying we have direct access with God and that we even rule with God. But is not-yet because even though we are in the kingdom where Christ rules, there is tribulation and we're called to endurance, the perseverance that will take us through to the consummation when Christ returns (v. 9).
In summary, some initial principles in understanding Revelation include:
(1) Read and learn the Old Testament passages that Revelation refers too.
(2) Understand that Revelation is communicating through symbolism, symbolic images, numbers, and other language which refer to the reality behind the symbols.
(3) We live in the "Already-and-Not-Yet" period Revelation is talking about. We are living in the latter days. What Revelation talks about has begun, but it is not complete, it has not reached its consummation. That is yet to come.