The Book of Revelation has had a sorted existance, especially in today's pop culture. Many read this book literally and foresee a horrific End of the World. Many read about the seals, the dragons, the serpents, and imagine an ultimate evil. Thinking about the number 666, the number 144,000, the number 7. Fortunately, these flowery pictures are only meant to be pictures and not truths. The Book of Revelation is a book of symbols.
First, I just want to inform you that I am using the New American Translation of the Bible that I will quote from. I will also provide references for the King James Version of the Bible.
The Book of Revelation was written during the beginnings of the early Christian church. A man by the name of John wrote this controversial book while he was in exile on the island of Patmos from the Roman Government. John was one of the lucky ones. Fellow Christians who weren't exiled were being stoned and persecuted at the hands of the Romans. John decided to write the Book of Revelation to give his fellow Christians hope for the future. Admittedly, times were hard for early church members, but John reminded them the struggle was worth it for Heaven.
The first chapter (NA and KJV Rev 1:11) reads, "...'Write on a scroll what you see and send it to the seven churches...'" These seven churches are both symbolic and practical. In Hebrew, the number 7 is regarded as a perfect or full number. The seven churches are to represent the fullness of the church. Realistically, these churches listed were cities in which John's writings would have visited. John intended this book to be a circular letter that would travel throughout the Christian community, and these seven cities were probably cities that were to receive the letter.
Later John refers to the seals. Rev 7:4 of both versions reads "I heard the number of those who had been marked with the seal, on hundred and forty four thousand marked from every tribe of the Israelites." You might recognize the 144,000 from Jehovah's Witnesses "Are you part of the 144,000?" If taken literally, this 144,000 people are the only ones who will get to Heaven. If taken symbolically, this 144,000 people represents the entire church. 144,000 is equal to 12 x 12 x 1000. The twelves represent the twelve tribes of Israel. The 1000 represents infinity. In Hebrew, the number one thousand was symbolic of infinity, much like something like gazillion means now.
The number 666 has taken a sort of Satanic or Evil symbolism. This so-called 'Devil's Number' is merely symbolic of Emperor Caesar Nero. John refers to several beasts in Chapter 13 of both versions. In Rev 13:17-18 the New American translation reads "(17) so that no one could buy or sell except one who had the stamped image of the beast's name or the number that stood for its name. (18) Wisdom is needed here; one who understands can calculate the number of the beast, for it is a number that stands for a person. His number is six hundred and sixty-six."
The picture of the chapter is that of two beasts that persecute all who don't believe in them, or all who do not carry their symbol of 666. In Hebrew, the 666 was representative of most evil. I said before that 7 was perfect and full. The number 6 stood for evil, impure, not full. One analogy I've been told is that of losing a game by one point. You feel really bad when you lose by one point because you were so close to winning. This sort of explains how 6 can be seen as imperfect and impure. Also, Hebrew carries no comparative or superlative forms of words. In order to create, create the idea of 'better' out of the word 'good', the Hebrew language would just repeat 'good'. Therefore, 'better' would be 'good good.' Similarly, the idea of 'best' would be 'good good good.' This explains why 6 was repeated 3 times to represent evil. So how are the Romans symbolic of evil? The early Christians were being persecuted by the Romans under Emperor Nero. The beast with the inscription and the people who beared the symbol of the beast were all depicted as forces that were doing evil.
Finally, the reason for the apocolyptic style. The reason why everything was written in symbols is for cover. John had to write this book in symbols so the Romans couldn't understand it, or more importantly, recognize it as Christian literature. Thus, instead of saying "Beware Emperor Nero and the Romans," he wrote "Beware the beast and all those bearing the inscription 666."