Johannes moves against this position in suggesting that there is an absolute duty to God; that is, that there are cases--for instance, Abraham's--where one should act in opposition to all universal ethical principles.
A Hegelian might identify God with the Absolute Mind, that is, as the embodiment of the universal truth. To attain this truth, we must suppress our individuality and participate instead in the universal. There is no private relation to God because we must forgo our privacy in order to come into contact with God: as a result, we can only speak of God in the third person. Johannes seizes on this point in suggesting that the knight of faith can speak to God in the second person singular. Most languages, including English until a few centuries ago, have two different forms of "you." The singular ("thou") is more intimate and friendly. The plural ("you") is used to speak either to more than one person, or to speak with formal distance. Johannes suggests that the knight of faith has an intimate relation to God.
Johannes argues that the knight of faith acts in total isolation from everyone else. His relation to God is a private one, and cannot be justified by an appeal to the universal. Faith, Johannes argues, is precisely that paradox that the single individual is higher than the universal. Though it is noble for the single individual to aspire to the universal, God may call for actions that cannot be justified in the universal.
In acting as a knight of faith, Johannes suggests, one is constantly being tested. One is being asked to act against the ethical, to abandon entirely one's own judgment as to what is right, and to act in unquestioning obedience to God. Either Abraham was obeying God or he was a murderer, and it took great faith for him never to question himself or to question God, never to doubt that he might in fact be a murderer. The temptation, then, is to comply not with faith, but with the universal, to do what one knows is right. This temptation is far stronger than any temptation to pursue personal, unethical pleasures. The temptation in that case is to do what one knows is wrong; the temptation for the knight of faith is to do what he knows is right. He is constantly being tested, because the option to follow his moral judgment is always available to him.
This section of the text contains the only mention of "fear and trembling," an allusion to Philippians 2:12-13. The passage urges Christians to "continue to work out your salvation with fear and trembling, for it is God who works in you to will and to act according to his good purpose." This "fear and trembling" seems appropriate for the constant testing that a knight of faith undergoes. The knight of faith must recognize that it is God who works in him, and that he cannot question or doubt. He must necessarily face this test with fear and trembling since he is going against the ethical and he knows that the option to retreat into the ethical is always open to him.
This "fear and trembling" is central enough to the message of the book that Kierkegaard chose it as a title. No doubt, the choice of title was partly inspired by Kierkegaard's poetic flair, but it also suggests a spirit of Christianity that he feels is lost in his age. In an age when Hegel's universal is esteemed, in which the public, the outer, the open is valued, we lose a sense of the privacy and the anxiety with which one enters into a relationship with God. Johannes suggests that either this privacy exists and Hegel is wrong, or Abraham is a murderer. With typical irony, he leaves it to the reader to decide which is correct.