Paul didn't rely on his own opinions. He rooted his arguments in a source his listeners already respected.
The Power of Shared Authority
Paul 'reasoned with them from the Scriptures.' This means he used the Old Testament – the Law and the Prophets – which both he and the Jewish audience recognized as divinely inspired. He wasn't introducing a foreign text; he was demonstrating how Jesus fulfilled their own sacred writings.
Explaining and Demonstrating
His method was to 'explain and demonstrate' (as suggested by the original language). He opened up the Scriptures, showing how prophecies pointed to the Messiah's suffering and resurrection, and then proved that Jesus fit this prophetic mold perfectly. This approach aimed to convince them not by force, but by logical, God-given evidence.