"Now it happened in Iconium that they went together to the synagogue of the Jews, and so spoke that a great multitude both of the Jews and of the Greeks believed. But the unbelieving Jews stirred up the Gentiles and poisoned their minds against the brethren. Therefore they stayed there a long time, speaking boldly in the Lord, who was bearing witness to the word of His grace, granting signs and wonders to be done by their hands. But the multitude of the city was divided; part sided with the Jews, and part with the apostles. And when a violent attempt was made by both the Gentiles and Jews, with their rulers, to abuse and stone them, they became aware of it and fled to Lystra and Derbe, cities of Lycaonia, and to the surrounding region. And they were preaching the gospel there" (Acts 14:1-7).
After leaving Antioch in Pisidia due to being expelled from the region, Paul and Barnabas travel to Iconium and continue their evangelistic efforts. They begin in the synagogue, as was their custom, and were successful in attracting a large crowd to not only hear the gospel but believe it (i.e., they obeyed the gospel). It should be noted that the faith of those who believed was based upon what they heard spoken; faith was not created in the hearts of people miraculously by the Spirit (cf. Rom. 10:17)! Sadly, however, the "disobedient" (which is a better rendering here than "unbelieving") acted swiftly to incite opposition to the truth. They were not willing to ignore the preaching which they rejected but desired to fight against it. Disobedient Jews stirred up the Gentiles, poisoning their minds against the church. How did they accomplish this "poisoning"? Certainly not with sound reason and a love for the truth but by twisting and perverting the message of hope and deliverance (cf. II Pet. 3:16).
Although many rejected them and their message, this did not deter Paul and Barnabas from remaining in that area a long time as they continued preaching boldly and working wonderful miracles to confirm the truth. They were not intimidated or scared by the resistance. The city was divided, however, in its allegiance. Some sided with the church and God's truth, but others were vehemently against such and supported the unbelieving Jews. Divisions of this sort are not uncommon, even today. When the gospel is preached with a proper attitude it often divides even friends and family (cf. Matt. 10:34-39).
Eventually, a violent attack was planned against Paul and Barnabas and they, becoming aware of it, fled to another city and continued preaching the gospel. Clearly, there is nothing wrong with avoiding persecution if you are able to do so without compromise (cf. Matt. 10:23)! They didn't flee because they were afraid; they would accept martyrdom when necessary. But, for now they preferred to keep evangelizing!
As a side note, Paul and Barnabas are both indirectly referred to as "apostles" in Acts 14:4 (and explicitly in 14:14). We understand that Paul was called directly by the Lord to be an apostle (cf. I Cor. 15:7-11), but how can it be said that Barnabas was an apostle? The answer to this question is found in understanding that the term "apostle" can be used in a couple different senses. The word literally means "one who is sent forth." The twelve were selected, specially trained, and sent forth by the Lord for a special work. These men (including Mathias and Paul) were known as apostles in a more formal sense of the term. The term "apostle" is also used (in Barnabas' case, for example) in a less formal sense to refer to someone who was sent out by a congregation on a special mission of some kind. In this context, both Paul and Barnabas were special messengers sent out by the church at Antioch to preach the gospel of Christ (cf. Acts 13:2,3).