The prayer meeting in Antioch was world-changing. It is hard to escape the effectiveness of the prayers of this young church. When they fasted and prayed, the Holy Spirit told them what to do. It doesn't record that they asked, or that they were fasting for direction in this missionary venture. It was God's agenda and He delivered it during their prayer meeting. . . and they followed it.
The proconsul in Cypress believed and was amazed. The magician received some serious consequences for opposing Paul and Barnabas. Twice it records they spoke, "the word of God."
Paul's sermon rehearsed God's promises and faithfulness in order to get the Jesus. This is a key characteristic of apostolic preaching. He started with Moses, not Abraham. The synagogue leader had asked him to speak. He probably got more than he bargained for.