What inner change happens to people every time they reject God?
Each rejection hardens the heart: saying no becomes easier than before, rebellion grows, and awareness of God's mercy shrinks. Repeated resistance builds barriers until breaking through becomes increasingly difficult, and by old age a rebel against grace may be almost impossible to reach.
Les teaches that when a person is confronted with the choice for or against God and says no, the next time it is easier to say no than the last time. Their whole concept of rebellion grows while their concept of recognizing God's mercy gets smaller. He illustrates this with Pharaoh, who repeatedly refused to let the Jews go. Les explains that this is true of human nature today: every rejection makes it harder later to break down barriers of resistance, and people can become so hardened that it is almost impossible to get through to them, especially if they remain rebels against the grace of God into old age.