At Iconium Paul and Barnabas went as usual into the Jewish synagogue. There they spoke so effectively that a great number of Jews and Greeks believed. But the Jews who refused to believe stirred up the other Gentiles and poisoned their minds against the brothers. So Paul and Barnabas spent considerable time there, speaking boldly for the Lord, who confirmed the message of his grace by enabling them to perform signs and wonders. The people of the city were divided; some sided with the Jews, others with the apostles. There was a plot afoot among both Gentiles and Jews, together with their leaders, to mistreat them and stone them. But they found out about it and fled to the Lycaonian cities of Lystra and Derbe and to the surrounding country, where they continued to preach the gospel.
This is the very heart of Acts. Paul is on his first missionary journey. Here he is in the centre of modern-day Turkey, preaching the good news i.e.- telling people about Jesus. Some become believers but most remain unbelieving. This experience of a few becoming believers but most not is, of course, exactly the same today.
Maybe you can think of a few examples of this ‘believing and not-believing’. Signs and wonders i.e.- healings happen, and Paul and Barnabas continue with real boldness. Then the trouble starts.