What does the Bible say about hardening hearts?

In Hebrews 3:7-19, the writer emphasizes the peril of hardening our hearts when we hear God's voice. This hardening is a spiritual condition that leads to a failure to believe and can result in exclusion from God's rest, much like the Israelites who failed to enter the Promised Land due to unbelief. The passage reflects that our response to God's invitation is crucial; if we ignore or resist His call, our hearts can become unresponsive, leading us away from faith and assurance in Christ.