What I'm talking about, and it isn't surprising that a Catholic would misunderstand, is that "preaching the Gospel" means telling the plan of salvation and nothing else. It would be like you went to church and Sunday after Sunday the only thing the preacher talked about was how Jesus died on the cross for our sins and you believe in Him, receive Him as Savior and you are saved. There's nothing wrong with speaking the truth but if this was the only thing the preacher EVER spoke of, the congregation would never grow beyond in their faith. He would never learn about the plan God has for our lives, how he wants us to live in holiness and that we are indwelled with the Holy Spirit who gives us the power to overcome sin in our lives and grow in our faith. What Paul called the "meat" of the word. The REST of what the Bible teaches.
I realize that for many Catholics, the "gospel" means Matthew, Mark, Luke and John - the books in the Bible known as the Gospel according to... But what I'm talking about is the "Gospel", the good news that Christ died for our sins, was raised for our justification and by believing in Him, we have eternal life. Is that more clear?
The Proclamation of the Kingdom of God and the Call to Conversion started with Jesus Christ, though. And HIS words are in the Gospels, although Paul quotes him quite regularly. But the direct quotes are in the Gospels.
Of course then Jesus sent out the 12, and then the 72 and eventually we have the reading from the last chapter of Matthew as Christ is about to ascend into heaven — go out to all the nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit.
I understand you calling the entire Bible, the good news, but I still like to think of the Gospels as the words and deeds of Jesus Christ.
God bless you.