From Introduction to the Old Testament by Yale Professor Christine Hayes:
With Jacob, who is now Israel, God seems perhaps to finally have found the working relationship with humans that he has been seeking since their creation. God learned immediately after creating this unique being, that he will exercise his free will against God. God saw that he had to limit the life span of humans, or risk creating an enemy that was nearly equal to him. So he casts the humans out of the Garden, blocks access to the tree of life. But humans continue their violent and evil ways, and in desperation, God wipes them out, and starts again. This second creation proves to be not much better. They forget God, they turn to idolatry. God has promised at this point, however, not to destroy all humankind again, so he experiments with a single individual of faith. Abraham’s faith withstands many a trial. He is obedient to God in a way that no one has been up to this point in the narrative, but perhaps ultimately the model of blind obedience is rejected, too. When Abraham prepares to slaughter his own son, perhaps God sees that blind faith can be as destructive and evil as disobedience, so God relinquishes his demand for blind obedience: he stops Abraham himself.