Four simple points to guide any sane reading of Revelation.
1) Revelation is a book of the Bible. It is packed with Old Testament language and imagery, and cannot be understood without that Old Testament background. One scholar has suggested that Revelation uses the Old Testament “compositionally” rather than “expositionally” – there is no commentary on biblical texts (as in, say, Romans), but the Old Testament provides the palette from which Revelation is painted. Attempts to explain Revelation primarily by reference to Roman history or current events forget this principle.
2) Revelation is a book of the New Testament. It is not an alien oddity tacked on to the end of the Bible. It deals with the same issues and battles that the rest of the New Testament deals with. It should be read in the light of Paul’s letters, Acts, and, yes, the gospel of John.
3) Revelation is a pastoral letter (cf. the greeting in 1:4 and benediction in 22:21). It contains seven brief letters, and it is itself a letter. Like Paul’s letters, it is addressed to specific people at a specific time concerning specific threats and opportunities.
4) Revelation is a call to martyrdom. Martyrs cry out for vindication at the beginning, and when they are finally vindicated at the end, the world collapses and is reborn. Revelation shows that martyrs follow the path of Jesus, through suffering to glory.