God knew those Jews and God-fearing Gentiles who truly loved Him and lived for Him. When the apostles went from city to city, preaching the good news of Jesus the Messiah and the kingdom of God, those Jews and Gentiles who heard and believed were those who had been sincerely seeking God before the apostles arrived.
The gospel was not so much changing people’s’ minds about God as it was revealing people’s minds about God. Those who had a heart for God were accepting the gospel, and those whose hearts were hardened toward God were rejecting that same gospel.
Lots of religious people were rejecting the gospel. That’s because their hearts were hard before they ever heard the gospel.
Thus the book of Acts shows how God picked the ripe fruit and discarded the rotten fruit.
Scripture quotations taken from the NASB, unless otherwise noted.