But the magicians of Egypt did the same by their secret arts. So Pharaoh's heart remained hardened, and he would not listen to them, as the LORD had said. Pharaoh turned and went into his house, and he did not take even this to heart.
The great lesson from Exodus is that God is in control. And the last person to learn this the hardest way possible was Pharaoh. I have always found it odd that the magicians of Egypt would duplicate the water being turned to blood. It seems that Egyptian could dig wells as a new source of water. The magicians immediately showed Pharaoh they could do the same thing. However, what is telling is that they were absolutely powerless to undo the plague. They weren’t much help were they?
The power that confronted Moses was the power of a corrupt human heart. And human hearts will naturally defy God. They will deny Him outlandishly. This is as defiant as Richard Dawkins asserting that there “probably is no god, so get on with your life and stop worrying.” This does not offer much perspective. And it offers no solution to the plague of sin or the devastation of the inevitable judgment of conscience that all humans feel.
When the powers that be deny God, the reality is that God becomes more clearly in control. That is what we see in Exodus. Pharaoh holds on to his kingly authority only as long as God lets him. Eventually God will move so decisively that not even the most powerful human on earth can resist him.