Why did Paul and Barnabas flee to Lystra and Derbe?
Paul and Barnabas fled to Lystra and Derbe because an assault was formed by Gentiles, Jews, and their rulers to use them despitefully and to stone them. Becoming aware of the plot, they escaped to those cities, then continued to Lystra, where much the same opposition occurred.
Les explains that in Iconium the unbelieving Jews stirred up the Gentiles and made their minds evil affected against the brethren. Paul and Barnabas abode a long time speaking boldly in the Lord, which gave testimony unto the word of his grace, and granted signs and wonders to be done by their hand. But the multitude of the city was divided; part held with the Jews that Paul and Barnabas were false teachers, and part with the apostles and became followers of Paul and Barnabas. When an assault was made by both the Gentiles and the Jews and their rulers to use them despitefully and to stone them, they were aware of it and fled to Lystra and Derbe. Les notes they then go on to Lystra, where much the same thing happens. Later, certain Jews from Antioch and Iconium came to Lystra, persuaded the people, and having stoned Paul, dragged him out of the city, supposing he had been dead. Les ties this timing to 2 Corinthians chapter 12 and suggests that while Paul was unconscious after being stoned and dragged out for dead, God gave him an even greater experience.