The first challenge was to convince the Israelites, to change their despair to hope. In Ex 6:2-9, God spoke to the people through Moses:
a. He identified Himself as the God of their forefathers, though He did not tell them His name.
b. He repeated the promise to give Israel the land of Canaan.
c. He promised to deliver them from Egypt "with an outstretched arm and with mighty acts of judgment" (Ex 6:6).
d. “I will take you as my own people, and I will be your God “ (Ex 6:7).
The Israelites did not believe Moses, "because of their discouragement and cruel bondage" (Ex 6:9).
The next 6 chapters (7-12) described the judgment visited on Egypt because of Pharaoh's hardness of heart. These events are described in great detail, the purpose being to depict the power of God. It was a "shock and awe campaign." However, the purpose was not merely to terrify the Egyptians, but to impress on Israel the presence and power of God -- if He could perform these signs against Egypt, they could trust Him to take them to Canaan and defeat any other enemies they faced.
God struck Egypt with a series of plagues:
a. water changed to blood (Ex 7:14-24)
b. frogs (Ex 8:1-7)
c. gnats (Ex 8:16-9)
d. flies (Ex 8:24)
e. cattle die (Ex 9:5-7)
f. boils (Ex 9:8-11)
g. hail (Ex 9:22-6)
h. locusts (Ex 10:12-15)
i. darkness (Ex 10:21-23)
j. death of the firstborn (Ex 12:29-30)
These acts of judgment on Egypt, particularly the culminating slaughter of innocents, have been a theological and public relations problem ever since the birth of humanism/modernism. There is no way to put a gloss on such wanton destruction. Several factors make God's actions and character incomprehensible to many spiritually-minded people:
a. Rather than being an exceptional act, the mass killing of hostile people is one of the key racial themes of the Old Testament. (It is ONE of the key themes, not the only one.) It was pre-figured in the Flood, and it was standard procedure in Canaan during the invasion. It is foretold in the final judgment. Many people ask -- what kind of God can send millions of His creation to hell?
b. Worse, in Egypt, thousands of innocent families were made to suffer for one man's disobedience -- Pharaoh's. Even "the firstborn of the prisoner, who was in the dungeon" (Ex 12:29) was killed. Even animals lost their oldest foal or calf (Ex 12:12). How could they be held responsible for wrongdoing?