In is list of eight words that describe the Gospel, D.A. Carson states that the Gospel is Biblical.
The gospel is biblical. “Christ died according to the Scriptures” (vv. 3–4).
It’s important that our hearers see that we preach the gospel from the Bible. An expository sermon demonstrably explains what the Bibles says. Demonstrably—that’s the crucial word. So at the end of the day people say, In truth that is what the Bible says. If someone wants to disagree with what I’ve said, they have to disagree with my understanding of the Bible, which they have every right to challenge me on, but the authority finally is the Bible and not me.
Defending the Bible is not the first responsibility of the preacher; preaching it is.