Why was the book of Revelation written? It was not written primarily, let me assure you, in order that people might be able to work out the date of the end of the world! That is a very grievous misunderstanding of the book.
The book of Revelation was written in order that God's people, who were passing through terrible persecutions and terrible adversity, might still be able to go on rejoicing. It is a book that showed them the ultimate victory of the Lord over Satan and all the other forces. They were to rejoice. It was written for men and women who had been in trouble, and was meant to primarily help them, not primarily for people who were to live two thousand years later.
And so it has been a help to Christian people in every age and in every generation. If your understanding of Revelation does not help you rejoice, then you are misunderstanding it.
- Martyn Lloyd-Jones