The Apostle Paul lived by his own teaching. He trusted that God had placed him in his historical moment and geographical location for a good purpose. Accordingly, he took every opportunity to speak of Jesus. He wasn't about to let a single moment of his life go by without using it to do something of real value - something that would last into eternity. So whilst in Athens, he turned the dubious religious practice of the people into a window through which they could glimpse the true and living God. In the city was an altar to an "Unknown God"; Paul took the chance to introduce them to each other.
I wonder what he would have made of 21st Century England. I am sure he would have been pleased to hear of its Christian heritage, but I am equally sure that he would have quickly picked up on our society's general ignorance of God and his ways. There are many who profess to believe "in God", and according to the most recent census, most of these profess to be members of the Christian faith - thereby suggesting that faith in the Christian God is the God in view. But scratch beneath the surface of this claim and what substance is there? For many people, God is actually largely unknown; at best, the subject of faded recollections of Sunday school teaching.
For the good of everyone the church needs to follow Paul's lead and proclaim clearly not only the God who "made the world and everything in it" (Acts 17:24), but particularly his Son Jesus - his death and resurrection and the eternal implications of these things (c.f. v31). God has made himself known in Jesus. It is a tragedy that so many do not know him. Are you playing your part to make introductions?