This book offers a reasonable understanding of John's revelation letter to the seven churches of Asia, a letter that is not like the rest of the Bible and is difficult to understand. John's revelation letter describes a terrible spiritual war that was fought between God and Satan--a war that was caused by a simple statement Jesus made (Matthew 16:18) when he said he would build his church and nothing could stop it. But Satan knew in order to fulfill his own purpose, which was to control the world himself, he must kill the church or it would be the end of him.
There is a parallel view of that spiritual war, however. It was also fought as a carnal war between the first-century church and the Roman Empire. John wrote about the spiritual forces of God as they battled against the evil spiritual forces of the devil and his angels. The carnal war that those spiritual forces caused, the war between the church and the Roman Empire, was described by Edward Gibbon (1737-1794) in his history of the decline and fall of Rome.
Gibbon only wrote history, and he did not consider his writings to be a description of anything that was going on in God's kingdom, but the writings of both John and Gibbon describe the extreme price first-century Christians had to pay to be faithful to God and to continue on establishing his church throughout the world.
This book compares the things that John saw take place in the spiritual world--the cause--with something that was quite like it, but happened in this physical world between Rome and the church--the effect, which was described by Gibbon in his history.