Although the term “existentialism” never appears in Kierkegaard’s writings, he is regarded as the founder of this philosophical approach. Kierkegaard believed that the value of philosophers’ thoughts should be judged by their lives rather than by their intellectual conceptions because ultimately, the individual’s life is the basis upon which he is judged by God. As important as a writer's work is to his existence, it is his life as a whole that ultimately matters to God. This is why Kierkegaard was attracted to the lives of saintly figures, especially biblical Abraham, who he called a “knight of faith.”
Kierkegaard and Nietzsche shared the realization that anything decided to be meaningful must come from within the individual. It is the human race itself that attributes meaning. In Kierkegaard’s Fear and Trembling and in Nietzsche’s On the Genealogy of Morals, each philosopher sets out to discover the importance of subjective human emotion, and the role of human freedom in the universe.
While Nietzsche’s immoral Superman is the embodiment of his philosophy, Abraham is the embodiment of Kierkegaard’s existentialist philosophy. For Kierkegaard, true individuality comes through surrendering one’s individuality. Abraham discovers his meaning in the cosmos through losing himself in God, but when one tries to explain this to another person, the explanation seems absurd.
Kierkegaard recognizes an existential duty to a Creator whose moral authority outranks all social norms. He views Abraham's near sacrifice of his son as a consequence of a “teleological suspension of the ethical” rather than as an expression of obedience to social norms (this assumes that child sacrifice was practiced among Abraham’s people). From Kierkegaard's perspective, the distinction between good and evil is dependent exclusively on God. Therefore it is possible for Abraham to live and act beyond the prescribed norms of his day to fulfill a spiritual destiny that he alone could fulfill.
In Kierkegaard's scheme it makes little difference whether the son bound was Isaac (as Jews claim) or Ishmael (as Muslims claim). The story is not about recognition of the first-born son (a social norm), but about the surrender of Abraham's very being in an existential sacrifice that by faith overcomes despair.
Ethical cases such as Abraham's are problematic since we have no public policy to guide our decision about whether Abraham is obeying God's command or is delusional. For this reason Kierkegaard’s existential philosophy can’t be used to formulate specific ethical guidelines for society. It is simply too personal and too subjective. However, for Christians it is extremely relevant because it points to the necessity of spiritual ascent, divine enlightenment, and a deepening of communion with God.
Kierkegaard found inspiration in both Abraham and in the lives of the saints, especially the sixth-century monk, John Climacus, who spent his days in solitude, prayer and fasting at the monastery on Mount Sinai. Climacus wrote “The Ladder of Divine Ascent,” a work arranged into thirty chapters or “steps.” Each step details the vices that the individual must conquer and the virtues that the individual must perfect in order to ascend the spiritual “ladder” to the Kingdom of Heaven. Here are some of his famous sayings:
Step 1: A Christian is one who imitated Christ in thought, word and deed. A lover of God is one who lives in communion with all that is natural and sinless.
Step 5: Repentance is a contract with God for a second life. A penitent inflicts his own punishment upon himself.
Step 9: If you forgive quickly, you, too, will be quickly forgiven.
Step 15: Purity is putting on the nature of angels. It is the longed-for house of Christ and the earthly heaven of the heart.
Step 17: He who has tasted the things on high easily despises what is below. He who has not, only finds joy in possessions.
Step 25: Humility is a divine shelter which prevents us from seeing our achievements.
Step 50: There remain three virtues that bind and secure the union of all: Faith, Hope and Love--- and the greatest of these is Love.
Kierkegaard published Philosophical Fragments using the name “John Climacus”. In this work, he poses 3 questions:
What is the relationship between history (temporal existence) and human consciousness (eternal existence)?
Is there any purpose or meaning to events in our temporal existence other than historical interest?
Is it possible to base eternal happiness upon historical knowledge?
Kierkegaard’s solution was to find a link between the historical/temporal and the eternal/non-temporal. He does that by explaining knowledge as miraculous. He agrees with the Socratic-Platonic view that there is no learning, since one can’t learn what one already knows. Drawing on John Climacus’ understanding of spiritual enlightenment, Kierkegaard argues that learning involves a mysterious change that takes place in the learner at a specific moment of his existence - a moment of enlightenment. In this moment, the learner is absolutely certain that he/she has grasped eternal knowledge. Kierkegaard maintains that this is miraculous and supernatural because it can only be initiated by God through a series of historical/temporal events. This learning (or enlightenment) is individual, subjective and unique for every learner.
Kierkegaard argues further that individuals are unable to know anything that is certain except through this supernatural intervention in history. In this sense, Kierkegaard is a Skeptic who doubts that humans are able of our own faculties to learn or know anything.
So what makes learning or enlightenment possible? Kierkegaard recognizes that human existence involves suffering, anguish, pain, sickness and death. That being our plight, we naturally desire an escape. This desire is very powerful. It is a yearning for the eternal that leads us to “leap into absurdity”.
What is the absurdity? For Kierkegaard, it is the supernatural intervention of the divine Person Jesus Christ entering history, making it possible for us to know that God exists. The existence of God can’t be proved by reason, by experimentation, by logic or through observation. Only by faith in this divine intervention can one hope to escape the suffering of this life and move from ignorance to enlightenment. Here we see how Kierkegaard’s “supernaturalism” is clearly the opposite of the naturalism of Nietzsche and the Romantics.
Whereas Nietzsche rejected the prevailing morality in favor of his unique brand of “immoralism”, Kierkegaard presents social norms as "the universal" measure of service to the community. Even human sacrifice is justified in terms of how it serves the community, so when Agamemnon sacrifices his daughter Iphigenia he is performing a tragic sacrifice in order that the Greek expedition to Troy may succeed. Were Abraham’s intention in sacrificing Isaac to gain worldly success, he would simply be another tragic hero like Agamemnon. But as Kierkegaard understands the story of Mount Moriah, it is Abraham’s absolute surrender to God that makes possible his receiving back his offering and much more. Kierkegaard explains, “Infinite resignation is the last stage before faith …for only in infinite resignation do I become conscious of my external validity, and only then can one speak of grasping existence by virtue of faith.”