Mark 1:1

The beginning of the good news of Jesus Christ, the Son of God. (nrsv)

Many things have been written regarding Mark 1:1. The computer picks it up in green since it's not an independent clause, in fact, it's not a clause of any type. Why did the writer of Mark put it there?
Since it doesn't contain a verb, it was the writer's intention that it's not to be included as the first statement of the first section of his first Story. Instead of being called Mark 1:1, we should look at it as the title for his work.