Genesis is full of weird relational episodes with sometimes inscrutable morality. But the lesson of Genesis 20, one of several stories in which, as Marilynne Robinson puts it, “the patriarchs act badly and the pagans act well,” is clear: Do not presume the moral fiber of people whose ethnicity—or, more pointedly, whose metaphysics—are different from yours. I feel disappointed to be feeling the need to say this.