All that God had to do to harden Pharaoh's heart, or to harden your heart, is to withhold His own grace.
R. C. SproulThe clearest sensation that a human being has when he experiences the holy is an overpowering and overwhelming sense of creatureliness. That is, when we are in the presence of God, we are humbled and become most aware of ourselves as creatures. This is the opposite of Satan's original temptation, "You shall be as gods.
R. C. Sproul