Can you expound on the term "gospel" used in Mark 1:1?
In the first verse of Mark Chapter 1, when it talked about “this is the gospel”, the word gospel is Euangelion. This was a Roman Greek word used in order to make a grand announcement during this time. Typically it was used to inaugurate and delegate laws, so it was very authoritative.
As the Roman hearers are listening to this in the catacombs of Rome, they can sit and know that this gospel they are hearing is the news of the Messiah, and is news they must hold on to especially when they are suffering such persecution.
In AD 64 with the great fire of Rome Nero was killing Christians but they are holding on to this truth: Jesus is the one they must hold on to. He is the good news. This is where it begins.