How do we know that God's sovereignty encompasses everything?

God's sovereignty is a central doctrine in Reformed theology, emphasizing that everything that occurs is in accordance with His divine will. John 12:39 states, 'Therefore they could not believe...' which connects to the broader understanding that God has decreed all things, including the hardening of hearts. This concept teaches us that God's plan is not thwarted by human actions; rather, He is in control of all circumstances. The assurance we find in God's sovereignty is that, regardless of how events unfold, He is executing His perfect will. Understanding this truth comforts believers that nothing happens outside of God's sovereign decree, including the hardening of hearts, which highlights His justice and righteousness.