Authors of Scripture clearly did not labour under the assumption that their works, whether standing alone or as a whole, would be formally sufficient. As one scholar wrote:
If you read the Greek text of Paul’s speech [at the Areopagus in Acts 17:22-31] as Luke reports it at the speed you might expect him to speak to a large gathering in the open air, it will take two minutes, or perhaps a little longer if you allow for a few well-judged rhetorical pauses. It is just possible that the court was busy that day, that Paul’s case was scheduled in between several others, and that the court officials told him (as I was once told in the House of Lords when we were debating “assisted dying” and far too many people wanted to contribute) that he could speak for only two minutes. But I find that highly unlikely. There is no evidence that the Areopagus rushed through business. And Paul, of all people, would not want to pass up a chance like this to address the highest court in the proud capital of ancient culture, the home of philosophy, the cradle of democracy. I suspect that he spoke for two hours, rather than two minutes. His speech would form a book in itself, but Luke has no space for such a thing within his own work. He has boiled it down to the bones. (N.T. Wright, Paul: A Biography [London: SPCK, 2018], 195; emphasis added; comment in square bracket added for clarification)
For more, see my lengthy essay (also available on Amazon as a book):