Soren Kierkegaard
As the author, Kierkegaard frequently draws upon his personal experience to make his arguments for faith. Coming from a scientific background, he appeals to reason to some extent. Simultaneously he relies upon his religious education to complete his theories of thought. He believes that both are necessary because reason will only bring a person so far before the freedom to choose must be exercised in the definition of that person's growth. Kierkegaard is a firm advocate for the spiritual as a function of the identification of the unknown and the unknowable.
God
For Kierkegaard, God is the ultimate Teacher. He is the one who brings person into a state of wakefulness by revealing elements of the unknown which could not previously become knowable to a human being. By becoming a man without sin, God created the ultimate paradox, which draws human knowledge into fruition by willing engagement with the dilemma. God invites people into freedom by offering them opportunities to accept their dependence upon Him due to factors beyond their control or ability to understand. At the same time God desires to be understood, so He extends external knowledge to people who seek after it.
Socrates
At the beginning of his discussion of thought, Kierkegaard appeals to Socrates. He uses Socrates' teaching as one half of his final product because the philosopher so thoroughly established a means of seeking Truth. Nevertheless, Kierkegaard believes Socrates was short-sighted in his discussion because he could never allow himself to step beyond reason into faith.