“some of them became obstinate, they refused to believe” [Acts 19:9(NIV)]

“some of them became obstinate, they refused to believe”. No matter how attractive the gospel message or how illustrious those who preach it, those who do not respond to it are likely to be hardened by it. The Church of Jesus Christ has grown through those who have responded, not on the doubters and dissenters.
The world is a great harvest field, as Jesus said, but when the message is refused, the evangelist must go and offer his treasures to others. This is just what Paul and his companions did. He left off preaching to the critics in the synagogues and began ministry to a group in the nearby school of Tyrannus. There they experienced great joy and blessing. Be obstinate and you’ll find you can’t believe. Be receptive and find you enjoy the blessing of God more and more.