Everything in the Christian life is dependent upon prayer. Thankfully, we serve a God who hears, answers, and has respect unto prayer.
Although there are times where God respects some while rejecting others, God’s acceptance of one and rejection of another is never a baseless respect.
The Bible seems to point to Pharaoh most often as an example of someone with a heart hardened through sin and the deceitfulness of power and fame. Pharaoh's hardened heart led him from one rebellious act to the next. He constantly fought against the Lord and the Lord’s man. Even after all of the miracles in Egypt and the abundance of judgments, he chose to pursue the children of Israel as they departed from Egypt. Pharaoh's hardened heart led him to pursue them to the Red Sea. Out of all the troublesome effects of a hard heart, the most troubling aspect is that it refuses to hearken to the words of the Lord. On at least five occasions, the Lord makes this connection (Exodus 7:13, 22; Exodus 8:15, 19; Exodus 9:12). A hard heart closes the ears to the truth and sets the individual up for greater judgment.