Does God harden the heart or does the individual harden his own heart?
The answer is, “Yes!” The scriptures tell us that God will harden the heart of a person at times, but it also says that we harden our own hearts. Here are two passages that state both are true,
But when Pharaoh saw that there was relief, he hardened his heart and did not listen to them, as the LORD had said. (NASB) Exodus 8:15
So then He has mercy on whom He desires, and He hardens whom He desires. (NASB) Romans 9:18
Now how are we supposed to understand what occurred? Should we assume that God hardened Pharaoh’s heart or that Pharaoh hardened his own heart? The answer is that both occurred. Both God and Pharaoh acted independently. It is a mystery like the mystery of the trinity, the incarnation of Jesus, the KENOSIS of the Christ, predestination and election, inspiration of the scriptures, and sanctification of the believer.
There are some great mysteries in the scriptures. This is one of them. God hardened Pharaoh’s heart, but Pharaoh is also accused of hardening his own heart. Ultimately, Pharaoh was responsible and suffered the consequence of his actions.
Reference Links:Peace With God
Time To Rest - Warning to not harden your heart