Paul and Barnabas enter into Lystra, a frontier outpost town, and as God heals a lame man, the people begin worshipping the missionaries as gods....and then they try to kill them. What we see in this passage is that all people are worshipers. That is how we are created. Even the most devout atheist worships. What we live for - what we put all our hope in - what we sacrifice everything for - that is what we worship. And the truth of God’s message always exposes and confronts our idols. The gospel calls us to "turn from these vain things to a living God" (Acts 14:15).
It is God alone who "satisfies [our] hearts...with gladness" (Acts 14:17). All other things we live for, find our identity in, or put our hope in are powerless to give what they promise. Only a living God who created us in His image, can give the hope of salvation, reconciliation, and relationship for which we were created. But as we see in this text (and all around us) human beings don’t give up their idols easily. To touch someones idol will bring forth rage and hatred. To say an idol - what a person has built their life and identity on - is a "vain thing" will incite a tidal wave of opposition. The people of Lystra won’t give up their "gods" easily. The unbelieving Jews who followed the missionaries here won’t give up their idols easily either. And when they lash out together, we see where Paul has placed his hope and his worship. He values Jesus more than his own life, comfort, and security. He has turned to a living God and calls us to do the same.