Why did God have to redeem Israel from Egypt?
God had to redeem Israel because His covenant people had been lost to Egyptian control and idolatry after Joseph's brothers' sin brought them there. Redemption meant buying back and paying the price to bring them back to Himself, just as sin separated Adam and Eve from God.
Les explains that Exodus is a book of redemption, meaning buying back or paying the price for something God once owned but lost. He draws a parallel to Adam and Eve: sin entered, separated them from God, and God instituted a plan of redemption. Likewise, when Joseph's brothers sold him into slavery and Joseph ended up in Egypt, their sin set events in motion, and God lost control of His covenant people. Israel was now in Egypt under the influence of Egyptian idolatry, so God had to pay the price to redeem them and bring them back unto Himself. This happens as God is ready to fulfill His promises to Abraham, Isaac, and Jacob and take Israel into the land delineated in the Abrahamic covenant.