Imagine taking your index finger and your thumb and rubbing them briskly together. Continue doing this, not for a short while as if relieving an itch, for an extended duration. If you kept this up for an hour or two the sides of your fingers would most likely turn red from irritation and would become sore. If you kept this up even longer then they would eventually become numb to the agitation and would callous over. What reasoning would you have for doing this to yourself, ruining the natural sensitivity in your fingers and causing yourself harm? To answer this question, you might ask yourself another ... why would you do this same thing to your heart through sinning repeatedly? The answer is not an easy one to give, because like a burglar spelling out his master plan to a jury, it is self incriminating. Although hardening our own hearts may not irritate us as much physically as rubbing our fingers together until they are sore, it is byfar more damaging to us spiritually. Because of its importance, we will be studying the process of how the heart becomes hardened to hopefully better prevent it from happening.

In the old Testament we have a few instances of hearts that had been hardened by God. God told Moses that he would harden the heart of Pharoah in Exodus 4:21. Moses was also told that God would harden Pharoah's heart in Exodus 7:3 and 14:4. So does God merely choose someone randomly whose heart he wishes to harden for no reason other than causing opposition to his people? Of course he does not. God is a just God (Psalm 62:12 and 89:14) and hardening a believing heart would not be according to God's revealed character. Prior to Exodus 4, Pharoah had already tightened his grip on the nation of Israel out of fear of their numbers (Exodus 1:8-11) and had ordered Hebrew midwives to kill males that they aided Israelite women give birth to (1:15-16), among other things (Exodus 2:15). Pharoah had already set himself up opposed to God and because of this, he was used to bring glory to God. In each of the verses where God tells Moses that he will harden the heart of Pharoah, God also includes the purpose of why he will be doing it. In Exodus 4:21-23 we find that God will harden Pharoah's heart so that Pharoah will not let the people of God go. From verse 23 of chapter 4 we can know that God planned from this point forward to use the already corrupted heart of Pharoah to execute his plan of freeing the nation of Israel that would carry through Exodus 14. The purpose he gives in Exodus 7:3 ("that I may multiply My signs and My wonders in the land of Egypt" - NASV) coordinates with the purpose he gives in Exodus 14:4 ("I will be honored through Pharoah and all his army, and the Egyptians will know that I am the Lord." - NASV) which is the same purpose he gives for hardening the hearts of the Egyptians (Egyptian army to be more exact) in Exodus 14:17.

So what application does this have to Christians and people in the world today? It emphasizes the fact that God will not deal indefinitely with people who have let their hearts become corrupted. In the first chapter of Romans, we are introduced to a group of people who Paul says were "without excuse" (Romans 1:20). These people knew God (Romans 1:21) yet they treated him as if they did not, participating in idolatry (Romans 1:23). Because of this, God gave them over to homosexual practices (which can be overcome like any other sin - 1 Corinthians 6:9-11), which Paul describes as a "depraved mind" in verse 28. All that we read happened to these people in Romans 1:24-32 happened because they had darkened their hearts (1:21). What makes a heart darkened? Look to Romans 2:5 where Paul tells another group of people who are "without excuse" that they have stubbornness and unrepentant hearts. This same idea is discussed by Paul again in a letter to the church at Thessalonica in 2 Thessalonians 2:11.