The three monotheist religious traditions, Judaism, Christianity, and Islam, have more in common than in contention. All three believe God is one, is unique, and is concerned with humanity's condition. These three monotheisms among all theistic religions bear a unique relationship to one another. Each takes up the narrative of the others. They tell stories of the same type, and some of the stories that they tell turn out to go over much the same ground.

Judaism, with its focus upon the Hebrew Scriptures of ancient Israel, tells the story of the one God who created man in his image, and of what happened then within the framework of Israel, the land of holy people. Christianity takes up that story, but gives it a different reading and ending by exemplifying the relations between God and his people in the life of a single human being. For its part, in sequence, Islam recapitulates some basic components of the same story. It affirms the revelations of Judaism and then Christianity, but draws the story onward to yet another climax.

We cannot point to any three other religions that form so intimate a narrative relationship. They share not only the common conviction that God is one and unique, but that He makes demands upon human social order and the conduct of everyday life. Each religion also distinguishes those who do God's will from the rest of humanity, and says that God will judge who is saved and who is not. Yet from these commonalities, differences have emerged that afford a perspective upon the others in this triplet group. What are the key issues in which they have diverged? There are five: the nature of God; the nature of people's relation to Him; how the people are to show their love and devotion; how they are to relate to those outside the religion; and what will happen in the End of Days.

Genesis 1:26 speaks of God's making man "in our image, after our likeness" ("our" refers to God's image). Yet there is also Commandment Ex. 20:4: "You shall not make yourself a graven image or any likeness of anything" in nature. What conclusions have the three religions drawn from such statements? At one end of the continuum, Islam insists that God cannot be represented in any way, shape, or form, not even by man, who was created in God's image. At the other end, Christianity finds that God is both embodied and eternally accessible in the fully divine Son, Jesus Christ. In the middle, Judaism represents God in some ways as being of the same substance as man, in some ways as wholly other. There is a continuum, then, in relation to idolatry (creating embodiments of God in physical form): Islam has no practice or tolerance of it, including among other religions; Judaism has no practice of it but is tolerant; Christianity does have some forms of idolatry.

In all three religions, God makes himself known to a particular person, a "you" that is not only singular—a Moses, a Jesus, or a Muhammad—but plural; all those who will believe, act, and obey. Islam, Christianity, and Judaism concur that the faithful within each sect form a distinct group. But, among all humanity, how does that group tell its story? Judaism tells the story of its faithful as an extended family, "Israel," all of whom are children of the same ancestors, Abraham and Sarah. The faithful adopt for themselves the narrative of a supernatural genealogy, finding within the family all who identify themselves as part of it by also making its story their genealogy. Islam takes the diametrically opposed view, dispensing entirely with the analogy of a family. It defines God's people, instead, through the image of a community of faithful worshippers. It sees Muslims as supporters of one another and caretakers of the least fortunate or weakest members of the community. Its "people of God" are ultimately extensible to encompass all humankind within the community of true worshippers of God. Here, Christianity takes a middle position. Like Judaism, it views the faithful as a distinct people, but, like Islam, it obliterates all prior genealogical distinctions, whether of ethnicity, gender, or politics. So Christians form "a people of the peoples," or "a people that is no people," using the familiar metaphor of Israel.