The Revelation of Jesus Christ (Revelation 1:1), given to the Apostle John, was a symbolic vision using “signs” (verse 1). These symbols are the rule, and literal interpretations are the exception.
When Jesus answered his disciples in Matthew 24 regarding his “parousia” (presence, mistranslated “coming”) and the end of the age, he also used symbols: fig tree (Israel), sun (gospel), moon (law), heaven (ecclesiastical organizations), stars (religious leaders), clouds (stormy trouble), trumpet (messages from God), wind (powerful troubles which will destroy sinful earthly organizations, nations), carcass (ransom sacrifice), etc. Many symbols are used and repeated throughout the Bible.
Revelation begins after Jesus’ resurrection in 33 AD, and leads all the way through history to his 2nd advent into the future peaceable kingdom (Revelation 21-22). It describes seven churches (Ephesus, Smyrna, Pergamos, Thyatira, Sardis, Philadelphia, and Laodicea), seven seals, seven trumpets, seven plagues. There are angels, beasts, dragons, false prophets, etc., and these all symbolically describe events and characters throughout history to the present, into the future.
Overall Lessons. Jesus’ first advent work was two-fold: to give himself a ransom for all (1 Timothy 2:5,6), and to establish a nucleus of his Church of 144,000. The seven churches outline seven periods of history. History traces how true Christians have suffered greatly (inquisition torture, slaughters of whole cities, eaten by lions, burned at the stake) for obedience to Christ. However, during these periods, God gave trumpet truths (the New Testament, justification by faith, interpretation of the book of Daniel) through human messengers (angels). Beast-like creatures (civil governments, antichrist-papacy, the devil) would unsuccessfully try to devour true believers.
Jesus’ second advent is symbolically shown by His return wearing crowns, having a sharp sword, leading heavenly armies, binding Satan, destroying the false ecclesiastical systems and the devilish earthly systems. Revelation 20-22 outlines the resurrection of mankind, their healing and learning righteousness, the final test (Little Season), and the glorious outcome of the third heaven (Christ’s just and righteous spiritual reign) and the third earth (return of human perfection and holiness on earth).
God desires to inform His children about His plans and purposes; however, it will take serious study of both Old and New Testaments and history to “rightly divide the word of truth.” Ephesians 1:7-10 (Weymouth translation) states it thus: “…so abundant was God's grace, the grace which He, the possessor of all wisdom and understanding, lavished upon us, when He made known to us the secret of His will. And this is in harmony with God's merciful purpose for the government of the world when the times are ripe for it–the purpose which He has cherished in His own mind of restoring the whole creation to find its one Head in Christ; yes, things in Heaven and things on earth, to find their one Head in Him.”
Hoping the two free online booklets, "The Day of Judgment" and "Revelation: How to Study & Have it Make Sense" will help in your understanding.