Why were Barnabas and Paul mistaken for gods in Lystra?

"When the crowd saw what Paul had done, they shouted in the Lycaonian language, “The gods have come down to us in human form!” Barnabas they called Zeus, and Paul they called Hermes because he was the chief speaker."

- Acts 14:11-12

Lystra was a town on the route between Syrian Antioch and Ephesus. Like many cities in that region, Greek influence was strong, and the people worshipped the Greek gods.

It seems that those who witnessed the healing by Paul and Barnabas did not grasp that the gospel being preached was of a different religion, perhaps because they could not understand the language used (Greek) well. The Bible records that they spoke in the Lycaonian language.

Zeus, king of the Greek gods, was often portrayed as a large bearded man. Hermes, his messenger, usually appeared as younger and smaller-sized. Perhaps the fact that the Lycaonians identified Barnabas as Zeus and Paul as Hermes may indicate something about their appearances! Also, as Paul was the main speaker, he was performing Hermes’ role as messenger of Zeus.