Word had gotten around to the Jewish believers in Jerusalem about all that Peter had done with the Gentiles. So many of them were still stuck in their old ways that they couldn't see all that God was doing through Peter. What is sad is that there are still so many churches today that are still like this. Peter begins to explain to them the events as they unfolded starting with the visions and ending with the the Holy Spirit ascending on the crowd. After hearing this the people fell silent and then began to glorify God for what He had done.
In these verses we see that the people who had run from their homes when Saul was out to get them were preaching to all the Jews they came in contact with on their journey. Only a few of these people reached out to the Gentiles and because of that God blessed them and hundreds came to know the truth.
Chapter 11: 22-24
News had reached to the church in Jerusalem all that was going on in Antioch. They once again being curious sent out Barnabas to investigate if it was all true. When he arrived he was pleased to see that the were in fact filled with the Spirit and he rejoiced with them. He could see all this and not be jealous of the fact that he had not had a part in their conversion or that the crowd of new believers were made up entirely of Gentiles.
Chapter 11: 25-26
Barnabas wanted Saul to minister with him in Antioch so he traveled to Tarsus to get him. They spend the next year preaching and aiding in the growing church. The outsiders remembered when the apostles had been there and how they followed Christ. They began to call these believers Christ-peoples or Christians. This is where we get our term from.
Chapter 11: 27-30
Many people began to see different prophets come out and begin to speak. One of these men was Agabus who said there would be a famine and indeed there was. The Gentiles who were now believers gathered up funds to help with the relief and sent it to Jerusalem. If they hadn't been taught the truths of the Lord they never would have been able to help out those people in need.