God's message with the plagues?

Ancient Egyptians worshiped many gods. Hapi, representing the spirit and essence of the Nile, was one of several associated with the river considered to be the sacred life line of Egypt, its source and sustainer. The frog-headed goddess Heqt, goddess of fertility, was believed to assist women in childbirth and control the frog population. The greatest of gods was the sun, called Aton or Amon-Ra, who ruled and protected by day but was thought to sleep when he disappeared at night. What message do you think God sent with the plagues?