The Hebrews who left Egypt had concrete proof of God’s existence and commitment to them. Yet when the time came for them to claim their promised land, they hardened their hearts against the Lord and refused to believe He would give them victory over the people living in Canaan. So they rebelled, resisting Joshua and Caleb’s pleas and coming up with justifications for their disbelief.
God responded with harsh discipline: 40 years of wandering in the desert until those adults who resisted Him were dead (Num. 14:33-36). Because He considered the lesson about their resistance and discipline so important, the Lord reiterated it in the New Testament (Heb. 3:7-11). He didn’t want people to repeat the Israelites’ mistake of hardening their hearts against Him.
The way to a hardened heart is gradual. It begins with unbelief—that is, hearing but not accepting all or part of God’s Word as true. Instead, a person rebels, choosing to manage his or her affairs without the Lord. This involves ignoring the conscience or justifying unscriptural behavior; eventually, the heart becomes so calcified that the individual is no longer affected by the whisper of God’s Spirit.
It is dangerous to persist in choosing our own way. Not only does the Lord discipline those who rebel against Him; He also withholds opportunities and blessings. If we take seriously God’s warning not to harden ourselves against Him, then we must choose to be obedient. Over time, as our heart grows more tender and receptive, we’ll find that we are unable to make a wrong move without being convicted by the Spirit.