Abraham’s sojourning in Egypt is a purposeful foreshadowing of Israel’s later experience, just as God separating light from darkness in the creation story foreshadows his separation of the Israelites from the Egyptians, becoming light to one and darkness to the other, as he liberated Israel from Egyptian bondage.
Genesis is just as much a story of the origins of Israel under the rule of YHWH as anything else. The creation story, the separation of the faithful from the nations, the Abraham story, including his sojourn in Egypt and return to the land of promise, and finally the recapitulation of this cycle in the story of Jacob, Joseph, the brothers, and the Exodus, all point to this aim of the Torah’s grand narrative. God was creating a people for himself to bless the world through his grace and creative power, within and through their vicissitudes and their struggles.
The sabbath school quarterly misses the whole point of the story while moralizing out of context what Abraham did, and focusing on an instance of disobedience that the Torah never terms as such.