Thousands of books exist theorizing its meaning, and many false doctrines rest upon these theories. All of us have heard amazingly interesting discussions of the Mark of the Beast, The Battle of Armageddon, The Millennial Reign of Christ, The 144,000, The Great Whore, and others. The story changes with each exponent. Knowing the nature of the book and man, God warned lest man fall into this trap. Unless one is positively sure the Bible supports his conclusions, he would be wise to leave this book alone.
Speculation usually results in contradiction.
Theories abound which contradict the rest of the Bible. The theory of Premillennialism, based primarily upon Revelation 20, contradicts almost every book of the Bible. While brethren generally have sought to be careful in their exegesis of the book, seeking to harmonize it with the rest of the Bible, many different views have evolved. Many brethren fear studying the book of Revelation. Some flinch when the book is mentioned.