What does the Bible say about God hardening hearts?

Scripture explicitly teaches that God hardens hearts, asserting His sovereign power over human will. Romans 9:18 states that, 'Therefore He has mercy on whom He wills, and whom He wills He hardens.' This maintains that God has the authority to determine the spiritual condition of each heart. An examination of Exodus 14:4 shows how God hardened Pharaoh's heart to accomplish His purpose, demonstrating that hardening is an active divine action rather than a passive withdrawal of restraint.

Reprobate hearts are not merely influenced by external circumstances but are actively shaped by God's sovereign will. This counters interpretations that suggest God's role is merely permissive, as the biblical narrative consistently reveals God's active involvement in the falling away of those who reject Him. Thus, God's hardening is purposeful, aimed at fulfilling His divine plan and bringing glory to Himself through judgment.