In the second section of the Book of Exodus, G-d begins the process that will lead to the redemption of the Jews from Egyptian slavery. After some preparations, G-d then begins to strike the Egyptians with plagues.
The first nine plagues can be divided into three sets of three, each of which was intended to teach Pharaoh and the Egyptians something about the belief in G-d:
• The first set of three plagues (blood, frogs, and lice) was intended to demonstrate G-d’s existence.
• The second set (the mixed horde, epidemic, and inflammation
of the skin) was intended to demonstrate G-d’s providence.
• The third set (hail, locusts, and darkness) was intended to demonstrate G-d’s supernatural power.
Thus, the plagues teach us that not only does G-d exist; He also directs the world and wishes to come to our aid, and that He can and does override the natural order.
--Daily Wisdom Volume 3