‘Many people today do not realize that “Gospel” was a specific genre of literature in the first century Roman Empire. Every time a new Caesar came to power, he would have Gospel accounts written about himself and then distributed throughout the empire. The Caesar Gospels included stories about how the new Caesar was born, how he grew up, and some of the superhuman miracles he performed during his life. The Caesar Gospels usually included promises about how the new Caesar was the “Son of God” who would bring peace to the entire world, and how as a result, every Roman citizen must proclaim Caesar as Lord.
One can easily see that in such an environment, the Gospels about Jesus written by Matthew, Mark, Luke, and John would be viewed as potentially treasonous. These four Gospels were making the claim that Caesar was not Lord; Jesus Christ was Lord. That Caesar would not bring peace; but Jesus Christ introduced peace to the world. That Caesar’s divine birth, wise teachings, and miraculous events were mere myth, but such things really did happen in the life, ministry, and teaching of Jesus Christ.’
source: Jeremy Myers, “Chapter 25: A Church That Proclaims the Gospel In an Understandable Way” in Eric Carpenter, Simple Church: Unity Within Diversity (2014), p. 251. Published by Redeeming Press.