The Romans were quite used to the idea of making peace by shedding blood on the cross - they did it all the time. Only, their idea wasn't to reconcile people, but to exterminate anyone who threatened the state.
Philip, who was a gifted evangelist was simply doing what evangelists do. He told people about Jesus. What he didn't know was that he was part of God's bigger, overarching, plan to bring people from every nation into the Christian community.
We love to sing about how big and powerful God is, but when it comes to practical issues we, all too often, limit God's ability to do things. We make ourselves, our choices and our abilities the centre of the universe. On balance; that's a mistake!