Paul’s speech in Athens (Acts 17:16-34) shows us how he constantly turned every opportunity he had into a proclamation of the gospel. He started where the people were, talking about their altar to an unknown god and quoting from their own philosophers, but went on to describe God as the creator and sustainer of all mankind, the ruler of all, the Father of all creation and the judge before whom justice would be served.
In so doing, he exposed the lack of logic in serving a multitude of gods. If God created everything and everyone, it is absurd to think He could be contained by a man-made building, however ornate it was! (Acts 17:24) If He sustains everyone, giving life and breath to us all, then it is absurd to think that He can be sustained by us. (Acts 17:25) We depend on God; He does not depend on us. The world was formed from one man (Adam) and all nations came from him. (Acts 17:26-28) The history and geography of all nations are ultimately under God’s control. His purpose is that humans (made in his own image) should seek him (or ‘feel after him’, a verb which ‘denotes the groping and fumbling of a blind man,’ as John Stott says.) If God is the creator, He can also be called the Father of all mankind, and therefore all idolatry such as was common in Athens is inexcusable because idolatry is the attempt either to localise God (confining him within limits which we impose) or to domesticate him (making him dependent on us.)
Paul begins his speech by talking about the altar of an unknown god and ends by talking of the people’s ignorance which has now come to an end because of all God has revealed and done through Jesus Christ. Now is the day of salvation, the day of repentance, an opportunity to be seized because judgment is definitely coming. The death and resurrection of Jesus mean He has been declared Lord and Judge by God and so the appropriate response is repentance and faith. Some in Athens took this step of faith and became believers. What is our response going to be?