Moses appears to the Israelites and Aaron provides the signs. They respond by believing in Moses as the deliverer and to worship since they are now going to be delivered from Egypt.

Moses appears to Pharaoh and requests an exodus. Pharaoh’s response is to increase the oppression of the Israelites. Then the Israelites turn on Moses. Note clearly that their reaction is not that they deny that YHWH is their God, but they deny that Moses is sent as His Deliverer. Their accusation is that Moses has elevated himself so as to receive glory in some sense and give Pharaoh an excuse to oppress them and destroy them.

Now that God has equipped His deliverer, He moves to deliver Israel from Egypt based on the Abrahamic Covenant and God’s specific prophecy in Genesis 13 and 15. He will first equip them by showing them He can deliver them from the greatest nation on the face of the earth. The Passover Lamb will be the means by which He delivers them. Thus, they will be equipped to realize that they must always approach God with His sacrifice, through which He will deliver them.