The signs and wonders which were previously done by the Twelve in Jerusalem and Philip in Samaria (Acts 2:43; Acts 5:12; Acts 6:8; Acts 8:6) are now also replicated by Paul and Barnabas. These miracles serve to confirm the truth of the message which they were sharing.1 In the literary context of Acts, they also confirm that Paul was an apostle with apostolic authority. It is important to remember that the apostles were instruments and not agents of miracles. That is to say, Jesus Christ was working through them; he is ultimately the one who does all the signs and wonders.2 It is possible that the miracles in Iconium enabled Paul and Barnabas to stay for a longer period of time in the city.3
3 So they remained for a long time, speaking boldly for the Lord, who bore witness to the word of his grace, granting signs and wonders to be done by their hands.