The central message of this sermon is that opposition and adversity serve a purpose in revealing God's power to judge evil and His glory to the world. The speaker argues that opposition shows not only the nature of evil but also provides an opportunity for God to demonstrate His power and authority, making Him known to all people. This concept advances the belief that God is sovereign over creation and that He works all things together for good (Romans 8:28). The takeaway is that God uses opposition as a means to get our attention and show us His glory, rather than simply avoiding it or trying to overcome it on our own.