In the first 9 plagues, God demonstrated that He is the only true God in contrast to the false Egyptian gods. Moses and Aaron speak to the Pharaoh with messages from God before each plague eventually ending in Pharaoh never wanting to see them again. A naturalistic explanation has been put forth to explain the plagues. However the plagues were given as God's justice to display Yahweh as the only God to the Israelites and Egyptians.