Why Don't People Respond to God's Power?

Exodus 7:8-13

8 The LORD said to Moses and Aaron, 

9 “When Pharaoh says to you, ‘Perform a miracle,’ then say to Aaron, ‘Take your staff and throw it down before Pharaoh,’ and it will become a snake.”

10 So Moses and Aaron went to Pharaoh and did just as the LORD commanded. Aaron threw his staff down in front of Pharaoh and his officials, and it became a snake. 

11 Pharaoh then summoned wise men and sorcerers, and the Egyptian magicians also did the same things by their secret arts: 

12 Each one threw down his staff and it became a snake. But Aaron’s staff swallowed up their staffs. 

13 Yet Pharaoh’s heart became hard and he would not listen to them, just as the LORD had said.