- The term "leap of faith" is discussed in Fear and Trembling. John Locke mentiones taking a "leap of faith" to Jack. The term is commonly attributed to Søren Kierkegaard, however, he never used that specific term, as he referred to it as a "leap to faith".
- Kierkegaard's "knight of faith" is described as someone who is nothing but the individual, without any connections or pretensions. The knight of faith is the individual who is able to gracefully embrace life. In Lost, there are many people of faith. Locke specifically calls himself a "man of faith". ("Man of Science, Man of Faith") and Ben refers to him as a "man of faith" as well. ("The Substitute") Eko and Desmond are two other people of faith from Lost. The overall concept of faith is the main topic in Fear and Trembling.