Acts 14:11-15
Acts 14:11 (KJB)
And when the people saw what Paul had done, they lifted up their voices, saying in the speech of Lycaonia, The gods are come down to us in the likeness of men.
Since many people were in this location, they saw what happened when this man became healed and was able to walk. Instead of giving God the glory for this miracle, the area was steeped in the false gods of Greece. They thought that some of the Greek gods had come down to visit Lystra. Paul and Barnabas probably did not understand the language of the Lycaonia area and although they saw the happiness of the people and probably thought they were rejoicing with the healing of the man but were unprepared for what they were about to encounter once they found out what these people were really saying. It was probably some type of Greek dialect but is unknown as what it exactly was.
Acts 14:12 (KJB)
And they called Barnabas, Jupiter; and Paul, Mercurius, because he was the chief speaker.
Once they started naming names, Paul and Barnabas then understood what they were doing. They had called Barnabas, Jupiter which was the Roman equal to Zeus. Then since Paul was the chief speaker, he was called, Mercurius or Mercury who was the Roman equivalent of the false god Hermes who was the chief speaker for Zeus. Now Paul and Barnabas knew what the townspeople were up to.
Acts 14:13 (KJB)
Then the priest of Jupiter, which was before their city, brought oxen and garlands unto the gates, and would have done sacrifice with the people.
The priest of Zeus had been notified that the gods had come down and now they were ready to put a wreath upon them and they brought some oxen to them and were planning on making a sacrifice to them. The people of Lystra were acting according to their religion by believing the false gods had come down to them. It was probably going to be a big feast.
Acts 14:14 (KJB)
Which when the apostles, Barnabas and Paul, heard of, they rent their clothes, and ran in among the people, crying out,
Crying - Called or screamed
Paul and Barnabas now finally realized what these people were doing as someone had probably interpreted the language for them. As soon as they found out what was happening, they had immediately tore their clothes as a sign of grief or dismay. They then immediately rushed into the crowd and began to speak in very loud voices.
Acts 14:15 (KJB)
And saying, Sirs, why do ye these things? We also are men of like passions with you, and preach unto you that ye should turn from these vanities unto the living God, which made heaven, and earth, and the sea, and all things that are therein:
Vanities - Empty, futility, worthlessness
Paul and Barnabas had tried to the best of their ability to stop this ceremony. They had told the people that they are not gods but they are men who are just like the rest of them. There was nothing supernatural about them. They completely misunderstood Paulís message in that they were not preaching about themselves but were bringing the true Gospel of the Lord Jesus Christ to them. He desired them to turn from the vanity of false gods unto the true and living God who was the creator of the earth, its fullness, and also the entire universe. Paul wanted to disabuse them of the idea that they were somehow more than human. He wanted them to know that they were representatives of the Lord Jesus Christ bringing the Gospel to them.