The first section of the book is a short one entitled "Exordium." It tells the story of a man who deeply admires the story of Abraham in Genesis 22, admiring it more and more as he grows older, but understanding it less and less. More than anything, this man wants to witness the event, to watch Abraham, in order to understand how Abraham did what he did. The man ponders over four possible scenarios, each accompanied by an analogy to a mother weaning her child.
In the first, Abraham explains to Isaac that he is to be sacrificed, but then pretends to be a homicidal psychopath, so that his son will blame Abraham, and not God, for his death, and not lose faith in God. The man draws the analogy of a mother blackening her breast in order to wean the child: the breast changes, but the mother remains the same.
In the second, Abraham did what God told him to do, but did it reluctantly and uncomprehendingly. Forever after, Abraham was changed, and unable to feel joy. The man draws the analogy of a mother concealing her breast so that the child feels it no longer has a mother to draw milk from.
In the third, Abraham assumes God is testing him in a different way, to see how dearly he loves his son. Abraham rides alone to Mount Moriah and begs God's forgiveness for having even considered sacrificing Isaac. The man points out that both mother and child mourn over the weaning, as the child will never be closer to the mother than to her breast.
In the fourth, everything goes as planned, but Isaac sees at the last moment that Abraham clenches the knife in despair. Forever after, Isaac's faith is lost. The man remarks that when a mother must wean her child, she has more solid food at hand to feed the child.
Johannes tells us that the man ponders these and many other scenarios, never managing fully to understand Abraham.
The story that is the focus of Fear and Trembling is told in Genesis 22:1-19. In this passage, God tells Abraham to bring his only son Isaac to Mount Moriah, and to sacrifice him there as an offering to God. Without protest or question, and without telling anyone else of God's command, Abraham saddles his horses and rides for three days with Isaac and his two servants to Mount Moriah. He then lays Isaac upon the altar, and raises his knife to kill Isaac. Only then does the angel of God stop Abraham, pointing out to him a ram caught in a thicket that he is to sacrifice in Isaac's place.
The story of Abraham is considered a perfect example of total faith by all three monotheistic traditions. Muslims consider Abraham to be the first Muslim, since the word "Muslim" signifies a complete surrender to the will of God. In the Exordium, Johannes shows how difficult it is to understand Abraham's seemingly simple deed. That is, how could Abraham accept God's word and travel all that distance without once faltering, without once questioning God, without once mourning his loss? The four imagined scenarios present alternatives of more easily understood behavior in these conditions. They also show how any more easily understood behavior could not stand as the foundation of faith.
The distinction which Johannes begins to draw here and which he will bring out in greater detail in the three Problemata is the distinction between the ethical and the religious spheres. The ethical deals with the single individual's place in human society, where the highest good is that which is of the greatest benefit to society as a whole. The religious goes beyond the ethical, and deals with the single individual as an individual in relationship to God. There is no way of justifying or explaining the behavior of a religious person, since that person's relationship is with God alone, and not with the rest of society. The four possible scenarios all present alternatives of ethical behavior, behavior which we might understand, but which are not Abraham's.
In the first, Abraham severs the bond of love between father and son in order that Isaac not lose faith in God. This is a noble sacrifice on Abraham's part, but not the one that God intended. In the second, Abraham follows God's command, but because he cannot understand God's wish in ethical terms he confused and sorrowful. He can no longer understand what goodness is, if God should demand such a horrific sacrifice. In the third, Abraham understands God's command as a test of his ethical fiber. That is, as a man in society, Abraham's first duty is to his son, and on those terms, Abraham should not sacrifice him at any cost. In the fourth, like in the second, Abraham follows God's command, but he also tries and fails to understand it. As a result, Abraham loses faith in God, and so does Isaac.
The most credible way of interpreting the analogies with the weaning of the child is to see Isaac as the child, Abraham as the breast, and God as the mother. Babies identify the mother's breast as the mother, since that is what gives them sustenance. When they are weaned, they come to see their mother as a person with whom they have a relationship, not simply as a source of food. Thus, the sacrifice could be read as a way of bringing Isaac into a closer relationship with God by weaning him from his earthly relationship with Abraham.
The first scenario, with the mother blackening her breast, brings Isaac closer to God by removing Abraham as an intermediary. In the second, when the mother conceals her breast, the child no longer has a mother: if Abraham is ruined by the sacrifice, Isaac cannot possibly be brought closer to God. In the third, we are given the sense that Isaac is closest to God through the intermediary of Abraham. The tie between those two is easier and more natural even if Isaac is not as aware of his relationship with God. The fourth suggests that the mother should have better food than the breast at hand in order to wean the child. Isaac loses faith because Abraham loses faith: he can see no stronger sustenance from God.
The man in the story fails to understand how Abraham acted as he did because he fails to understand the faith required. The fact of the matter is that Abraham's faith is beyond comprehension, and any kind of rational scenario that we construct will be unable to bring us beyond an ethical understanding of Abraham.