One of the reasons the apostles were so effective in Acts is that they saw opposition as an opportunity rather than an obstacle. They knew the devil fights hard against us because he is jealous of Jesus' victory, and stirs up people to be offended by the Word and our faith. When Paul's heart became provoked by how sin blinds and deludes people's minds, he went into the public space and explained how the "unknown God" the people of Athens were seeking is able to be found. He wanted to show that the insufficient false gods mankind follows are inadequate compared to Jesus--a calling we share in the discouraging times.  Video of this service is also available:  https://www.youtube.com/watch?v=VXZTrA9q9ao